Compositions and methods for oral delivery of crystalline PRX-3140 potassium salt

ABSTRACT

The present disclosure addresses this need by providing crystalline fine particle forms of PRX-3140 potassium salt, methods for preparation and the treatment for Alzheimer&#39;s disease (AD) and other dementias affecting the cholinergic and/or serotonergic systems including post-traumatic stress disorder (PTSD). In certain aspects, the present disclosure provides novel methods of preparing the compound of Formula I thereof, or PRX-3140 potassium salts, crystalline fine particle forms of PRX-3140 potassium salt, and compositions comprising them. In certain aspects, the present disclosure provides novel crystalline fine particle form of PRX-3140 potassium salt which may provide advantages including improved bioavailability and stability relative to other crystalline or amorphous forms. In other aspects, the present disclosure provides oral dosage forms of crystalline fine particle form of PRX-3140 potassium salt and excipients with improved stability. In additional aspects, the present disclosure provides novel methods of synthesizing novel crystalline fine particle form of PRX-3140 potassium salt, preparing crystalline PRX-3140 potassium salt particle delivery systems (PDS), and preparing novel final dosage forms (FDF) of crystalline fine particle PRX-3140 potassium salt. In certain aspects, the present disclosure provides novel crystalline forms of fine particle PRX-3140 potassium salt which may provide advantages including improved bioavailability and stability relative to other crystalline or amorphous forms.

BACKGROUND

The present disclosure relates generally to a novel crystalline form ofa compound of Formula I: ##STR00001 ##, also referred to as6,7-Dihydro-4-hydroxy-7-isopropyl-6-oxo-N-(3-(piperidin-1-yl)propyl)thieno[2,3-b]pyridine-5-carboxamidepotassium salt or potassium7-isopropyl-6-oxo-5-(3-piperidin-1-yl-propylcarbamoyl)-6,7-dihydro-thieno[2,3-b]pyridine-4-olate,particle delivery systems of the crystalline compound, methods ofpreparing such compositions, and therapeutic uses thereof. The compoundof the present disclosure was originally described in U.S. Pat. No.7,488,736 followed by U.S. Pat. No. 7,982,040 as well as foreignpatents. The crystalline potassium salt compositions described hereinallow the compound to be administered by routes that are non-invasive topatients, such as by oral administration.

The compound of the present disclosure, referred to in the literature asPRX-3140 or PRX-03140, is a selective partial agonist to the5-Hydroxytryptamine receptor 4 (5-HT4) and a ligand for the Sigma-1 andSigma-2 receptors. PRX-3140 is a highly selective and potent (Ki=22-37nM) 5-HT4R agonist in radioligand binding assays with more than 100-folddifference in affinities compared with all other 5-HT receptors tested.PRX-3140 behaves as a partial agonist in cell lines expressing eitherthe human 5-HT4aR, 5-HT4bR or 5-HT4eR isoforms, stimulating cAMPproduction to 30%-60% compared to 5-HT. PRX-3140 also demonstratesbinding to both the Sigma-1 and Sigma-2 receptors (Ki=79-100 nM and99-160 nM, respectively) in radioligand binding assays, but demonstratesno significant affinity for more than 50 other receptors testedincluding GPCRs, ion channels and receptor tyrosine kinases. Thespecific ligand binding to the receptors is defined as the differencebetween the total binding and the nonspecific binding determined in thepresence of an excess of unlabelled ligand. The inhibition constants(Ki) were calculated from the Cheng Prusoff equation(Ki=IC50/(1±(L/KD)), where L=concentration of radioligand in the assay,Kd=affinity of the radioligand for the receptor and Hill coefficient=1).

PRX-3140 is being developed for Alzheimer's disease (AD) and otherdementias affecting the cholinergic and/or serotonergic systemsincluding post-traumatic stress disorder (PTSD). Extensive non-clinicalstudies have been completed including in vitro and in vivo pharmacology,safety pharmacology, genotoxicity as well as single and repeat dosetoxicology studies in two species, rat and beagle dog. Early-stageclinical studies, including safety, tolerability, and pharmacokineticsof PRX-3140 demonstrates high oral bioavailability, as well as safetyand efficacy, of the compound up to 250 milligrams. Besides its highoral bioavailability, PRX-3140 achieves a brain/serum partition ratio of0.93 after 1 hour following oral administration in preclinical studies.PRX-3140 demonstrates high CNS penetration without inducing significantdistal gastrointestinal motility observed with gastrointestinally active5-HT4 agonists (e.g. cisapride, tegaserod).

Oral administration of drugs, such as PRX-3140, is generally preferredover intravenous administration for reasons of patient comfort andcompliance. However, many drugs are variably absorbed when deliveredorally. There has been substantial effort in the last decade to producedrug particles from 100 nanometers to a few hundred microns because oftheir improved dissolution properties and ability to be absorbed moreefficiently. Through a number of experiments, the present inventors havesurprisingly discovered new solid forms of PRX-3140 forms, comprisingthe fine particle crystalline form of the PRX-3140 potassium salt. Thiscrystal form has unexpectedly good properties and is more suitable forformulation processing, storage, industrial production, and has betterbioavailability. Compared with the known solid form of PRX-3140described in U.S. Pat. No. 7,488,736 followed by U.S. Pat. No.7,982,040, the fine particle crystalline form of the PRX-3140 potassiumsalt in present invention have at least one or more superior propertiesand achieve unexpected effects. Specific improvements are, for example,higher solubility in water, higher dissolution rate, better stability,lower hygroscopicity, better flowability and favorable processing andhandling characteristics. Preferably, the new solid form in the presentinvention has improved stability.

SUMMARY OF THE INVENTION

The present disclosure addresses this need by providing crystallinepotassium salt compositions of the compound, methods for preparation andthe treatment for Alzheimer's disease (AD) and other dementias affectingthe cholinergic and/or serotonergic systems including post-traumaticstress disorder (PTSD). In certain aspects, the present disclosureprovides novel methods of preparing the compound of Formula I thereof,or PRX-3140 potassium salts, crystalline fine particle forms of PRX-3140potassium salt, and compositions comprising them. In certain aspects,the present disclosure provides novel crystalline fine particle form ofPRX-3140 potassium salt which may provide advantages including improvedbioavailability and stability relative to other crystalline or amorphousforms. In other aspects, the present disclosure provides oral dosageforms of crystalline fine particle form of PRX-3140 potassium salt andexcipients with improved stability. In additional aspects, the presentdisclosure provides novel methods of synthesizing novel crystalline fineparticle form of PRX-3140 potassium salt, preparing crystalline PRX-3140potassium salt particle delivery systems (PDS), and preparing novelfinal dosage forms (FDF) of crystalline fine particle PRX-3140 potassiumsalt. In certain aspects, the present disclosure provides novelcrystalline forms of fine particle PRX-3140 potassium salt which mayprovide advantages including improved bioavailability and stabilityrelative to other crystalline or amorphous forms.

In certain aspects, the present disclosure provides a compositioncomprising a crystalline form of the potassium salt of the compound ofFormula I, ##STR00001 ## shown in FIG. 1 .

In some embodiments, a composition comprising a crystalline form of acompound of Formula I: ##STR00001 ## and wherein the crystalline Form I,characterized by an x-ray powder diffraction pattern comprising majorpeaks at 22.3.+−0.0.3.degree., 25.3.+−0.0.3.degree. and5.4.+−0.0.3.degree. two theta., and optionally further comprising atleast one peak selected from 25.8.+−0.0.3.degree., 15.9.+−0.0.3.degree.and 29.9.+−0.0.3.degree. two theta. In some embodiments, the x-raypowder diffraction pattern further comprises at least one peak selectedfrom 21.6.+−0.0.3.degree., 16.5.+−0.0.3.degree. and 20.3.degree. twotheta. The x-ray powder diffraction pattern may further comprise peaksat 21.3.+−0.0.3.degree., 17.1.+−0.0.3.degree., 16.3.+−0.0.3.degree.,33.1.+−0.0.3.degree., 45.6.+−0.0.3.degree. and 13.7.+−0.0.3.degree. twotheta. In some embodiments, crystalline Form I is characterized by anx-ray powder diffraction pattern substantially as set forth in FIGS. 3Aand 3B. In some embodiments, greater than 90% by weight of the compoundof Formula I in the composition may be crystalline Form I. In someembodiments, the compound of Formula I: ##STR00001 ## is Form I and ispresent in an amount ranging from about 0.01% to about 99.99% by mass ofthe composition. In some embodiments, the composition has an averagediameter of less than about 1 mm, 0.5 mm, or 0.3 mm. In someembodiments, the compound is stable for at least 12 months at5.degree.C. and 60% relative humidity or at 25.degree.C. and 60%relative humidity. In further embodiments, the formation of degradationproducts is less than 0.5 weight % per year at 5.degree.C. and 60%relative humidity or at 25.degree.C. and 60% relative humidity. Inadditional embodiments, the compound degradation products are FormulaII: ##STR00002 ##:5-hydroxy-8-(methylethyl)-8-hydro-1,2-oxathiino[6.5-b]pyridine-2,2,7-trione,or5-hydroxy-8-(propan-2-yl)-2H-2λ6-[1,2]oxathiino[6,5-b]pyridine-2,2,7(8H)-trioneand Formula III: ##STR00003 ##:[7-(methylethyl)1,4,6-trioxo(5,7-dihydrothiopheno[2,3-b]pyridine-5-yl)]-N-(3-piperidylpropyl)carboxamide,or1,4,6-trioxo-N-[3-(piperidin-1-yl)propyl]-7-(propan-2-yl)-4,5,6,7-tetrahydro-1H-1λ4-thieno[2,3-b]pyridinecarboxamide. In further embodiments, the composition is white or lightbrown color when the composition contains an amount of Formula II:##STR00002 ##:5-hydroxy-8-(methylethyl)-8-hydro-1,2-oxathiino[6.5-b]pyridine-2,2,7-trione,or5-hydroxy-8-(propan-2-yl)-2H-2λ6-[1,2]oxathiino[6,5-b]pyridine-2,2,7(8H)-trioneand Formula III: ##STR00003 ##:[7-(methylethyl)1,4,6-trioxo(5,7-dihydrothiopheno[2,3-b]pyridine-5-yl)]-N-(3-piperidylpropyl)carboxamide,or1,4,6-trioxo-N-[3-(piperidin-1-yl)propyl]-7-(propan-2-yl)-4,5,6,7-tetrahydro-1H-1λ4-thieno[2,3-b]pyridine-5-carboxamideless than 0.5 weight %.

In certain embodiments, a particulate delivery system (PDS) is describedcomprising a crystalline form of a compound of Formula I: ##STR00001 ##and at least one pharmaceutically acceptable excipient. In certainembodiments, the x-ray powder diffraction pattern further comprises atleast one peak selected from 22.3.+−0.0.3.degree., 25.3.+−0.0.3.degree.and 5.4.+−0.0.3.degree. two theta. In certain embodiments, the x-raypowder diffraction pattern further comprises at least one peak selectedfrom 25.8.+−0.0.3.degree., 15.9.+−0.0.3.degree. and 29.9.+−0.0.3.degree.two theta. In certain embodiments, the x-ray powder diffraction patternfurther comprises at least one peak selected from 21.6.+−0.0.3.degree.,16.5.+−0.0.3.degree. and 20.3.degree. two theta. In certain embodiments,the x-ray powder diffraction pattern further comprises peaks at25.8.+−0.0.3.degree., 15.9.+−0.0.3.degree., 29.9.+−0.0.3.degree.,21.6.+−0.0.3.degree., 16.5.+−0.0.3.degree. and 20.3.degree. two theta.In certain embodiments, the crystalline form of a compound of Formula Iis characterized by an x-ray powder diffraction pattern substantially asset forth in FIG. 3A or FIG. 3B. In certain embodiments, the particulatedelivery system contains greater than 90% by weight of the compound ofFormula I: ##STR00001 ## is Form I. In certain embodiments, theparticulate delivery system contains the crystalline compound of FormulaI: ##STR00001 ## is Form I and is present in an amount ranging fromabout 0.01% to about 99.99% by mass, about 10% to about 90% by mass, orabout 10% to about 50% by mass. In certain embodiments, the particulatedelivery system is formulated for oral, parenteral, or topical delivery.In certain embodiments, the particulate delivery system is formulatedfor oral delivery as a tablet, a caplet, a capsule, or a pill. Incertain embodiments, the particulate delivery system has an averagediameter of less than about 1 mm, 0.5 mm, or 0.3 mm. In certainembodiments, the pharmaceutically acceptable excipient is a polymer, awater-soluble polymer, and is chosen from starch, cellulose, orpolyethylene glycol. In certain embodiments, the particulate deliverysystem includes a second excipient and is chosen from magnesiumstearate, stearic acid, hydroxypropyl-beta cyclodextrin, silicondioxide, or mannitol. In further embodiments, the second excipient is asugar. In certain embodiments, the particulate delivery system isformulated for oral administration and may comprise 0.01 mg to 200 mg ofthe compound. In certain embodiments, the particulate delivery systemcontains the compound and is stable for at least 12 months at5.degree.C. and 60% relative humidity or at 25.degree.C. and 60%relative humidity. In further embodiments, the formation of degradationproducts is less than 0.5 weight % per year at 5.degree.C. and 60%relative humidity or at 25.degree.C. and 60% relative humidity. Infurther embodiments, the compound degradation products are Formula II:##STR00002 ##:5-hydroxy-8-(methylethyl)-8-hydro-1,2-oxathiino[6.5-b]pyridine-2,2,7-trione,or5-hydroxy-8-(propan-2-yl)-2H-2λ6-[1,2]oxathiino[6,5-b]pyridine-2,2,7(8H)-trioneand Formula III: ##STR00003 ##:[7-(methylethyl)1,4,6-trioxo(5,7-dihydrothiopheno[2,3-b]pyridine-5-yl)]-N-(3-piperidylpropyl)carboxamide,or1,4,6-trioxo-N-[3-(piperidin-1-yl)propyl]-7-(propan-2-yl)-4,5,6,7-tetrahydro-1H-1λ4-thieno[2,3-b]pyridinecarboxamide. In further embodiments, the particulate delivery system iswhite or light brown color when the composition contains an amount ofFormula II: ##STR00002 ##:5-hydroxy-8-(methylethyl)-8-hydro-1,2-oxathiino[6.5-b]pyridine-2,2,7-trione,or5-hydroxy-8-(propan-2-yl)-2H-2λ6-[1,2]oxathiino[6,5-b]pyridine-2,2,7(8H)-trioneand Formula III: ##STR00003 ##:[7-(methylethyl)1,4,6-trioxo(5,7-dihydrothiopheno[2,3-b]pyridine-5-yl)]-N-(3-piperidylpropyl)carboxamide,or1,4,6-trioxo-N-[3-(piperidin-1-yl)propyl]-7-(propan-2-yl)-4,5,6,7-tetrahydro-1H-1λ4-thieno[2,3-b]pyridine-5-carboxamideless than 0.5 weight %.

The present invention also describes methods method of making theparticulate delivery system of the compound of the composition,comprising: blending the composition together with an excipient to forma mixture; processing said mixture to form coarse particles having anaverage diameter ranging from about 0.1 mm to about 5 mm; and grindingor milling said coarse particles to form particles having an averagediameter less than about 0.5 mm. In a further embodiment, presentinvention also describes a method of making the particulate deliverysystem of the compound of the composition, comprising: blending thecomposition together with a polymer to form a mixture; processing saidmixture to form coarse particles having an average diameter ranging fromabout 0.1 mm to about 5 mm; and jet-milling said coarse particles toform particles having an average diameter less than about 1 micrometers.

In certain aspects, the present disclosure provides a method of treatingAlzheimer's disease (AD) and other dementias affecting the cholinergicand/or serotonergic systems, comprising administering an effectiveamount of the composition of the compound to a patient in need thereof.In a further embodiment, the present disclosure provides a method oftreating post-traumatic stress disorder (PTSD), comprising administeringan effective amount of the composition of the compound to a patient inneed thereof.

In certain embodiments, the present disclosure provides a method oftreating Alzheimer's disease (AD) and other dementias affecting thecholinergic and/or serotonergic systems in a subject, the methodcomprising administering to the subject a composition comprising acrystalline form of a compound of Formula I: ##STR00001 ##, wherein atleast 90% by weight of the compound of Formula I in the composition isthe crystalline form of the compound is Form I, characterized by anx-ray powder diffraction pattern comprising major peaks at22.3.+−0.0.3.degree., 25.3.+−0.0.3.degree. and 5.4.+−0.0.3.degree., andwherein the composition is prepared by blending the composition togetherwith an excipient to form a mixture; processing said mixture to formcoarse particles having an average diameter ranging from about 0.1 mm toabout 5 mm; and grinding or milling said coarse particles to formparticles having an average diameter less than about 500 micrometers.

In one aspect, the present disclosure provides an industrially scalableprocess for manufacturing a crystalline form of a compound of Formula I:##STR00001 ## and wherein the crystalline Form I, comprising the stepsof:

-   -   reductive amination of methyl 2-aminothiophene-3-carboxylate        with sodium triacetoxyborohydride in anhydrous dichloromethane        and formic acid under argon followed by work up with potassium        hydroxide to obtain methyl        2-iso-propylaminothiophene-3-carboxylate,    -   acylation and cyclization of methyl        2-iso-propylaminothiophene-3-carboxylate in pyridine and        butyronitrile with methyl malonyl chloride followed by addition        of sodium methoxide solution to obtain methyl        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate,    -   amidation and of methyl        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate        with 3-piperidin-1-yl-propylamine, and acidification with        hydrochloric acid to obtain        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide hydrochloride,    -   preparation of        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide potassium salt by adding        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide hydrochloride, MTBE, water,        potassium hydroxide solution, and sodium bicarbonate to give        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine        carboxylic acid (3-piperidin-1-yl-propyl)-amide followed by        dissolution in acetonitrile and addition of potassium hydroxide        in water to give crystalline        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140        potassium salt),    -   whereas the crystalline form of a compound of Formula I:        ##STR00001 ## and wherein the crystalline form of Form I is        obtained by grinding the powder and sieving.

In another aspect, the present disclosure provides a method of making acomposition comprising crystalline fine particle Form I of PRX-3140potassium salt, the method comprising:

-   -   blending crystalline fine particle Form I of PRX-3140 potassium        salt together with a stabilizer to form a mixture;    -   processing said mixture to form coarse particles having an        average diameter ranging from about 0.1 mm to about 5 mm; and    -   grinding said coarse particles to form particles having an        average diameter ranging from about 0.1 micrometers to about 0.5        mm.

In one aspect, the present disclosure provides an industrially scalableprocess for manufacturing PRX-3140 potassium salts thereof, comprisingthe steps of:

-   -   reductive amination of methyl 2-aminothiophene-3-carboxylate        with sodium triacetoxyborohydride in anhydrous dichloromethane        and formic acid under argon followed by work up with potassium        hydroxide to obtain methyl        2-iso-propylaminothiophene-3-carboxylate,    -   acylation and cyclization of methyl        2-iso-propylaminothiophene-3-carboxylate in pyridine and        butyronitrile with methyl malonyl chloride followed by addition        of sodium methoxide solution to obtain methyl        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate,    -   amidation and of methyl        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate        with 3-piperidin-1-yl-propylamine, and acidification with        hydrochloric acid to obtain        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide hydrochloride,    -   preparation of        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine        carboxylic acid (3-piperidin-1-yl-propyl)-amide potassium salt        by adding 4-hydroxy        isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide hydrochloride, MTBE, water,        potassium hydroxide solution, and sodium bicarbonate to give        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine        carboxylic acid (3-piperidin-1-yl-propyl)-amide followed by        dissolution in acetonitrile and addition of potassium hydroxide        in water to give crystalline        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140        potassium salt),    -   whereas the crystalline form of a compound of Formula I:        ##STR00001 ## and wherein the crystalline form of Form I is        obtained by grinding the powder and sieving.        In some embodiments, the present disclosure provides        crystallizing of an input        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide free base and acetonitrile        and addition of potassium hydroxide in water to provide        crystalline        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide potassium salt solid and a        mother liquor followed by separation and drying, wherein the        crystalline form of a compound of Formula I: ##STR00001 ## of        Form I containing greater than 90% the desired compound. In a        further embodiment, the present disclosure provides        crystallization by dissolving the input free base in        acetonitrile at a first temperature by heating from about        20.degree.C. to about 100.degree.C and then cooling the solution        to a second temperature. In a further embodiment, the present        disclosure provides crystallization by cooling the solution to a        temperature ranging from about 0.degree.C. to about 20.degree.C.        In a further embodiment, the present disclosure provides        crystallization by cooling the solution to a temperature ranging        from about 0.degree.C. to about 20.degree.C. for 0.5 hours to 10        days. In a further embodiment, the present disclosure provides        crystallization by cooling the solution to a temperature ranging        from about 0.degree.C. to about 20.degree.C. for 2 to 4 hours.        In a further embodiment, the present disclosure provides        separation of the crystalline solid and the mother liquor may be        by filtration, decanting, aspiration, or any suitable method. In        yet another further embodiment, the present disclosure provides        separation of the crystalline solid and the mother liquor may be        by filtration washed with solvent, and dried in vacuo to        constant weight. In a further embodiment, the present disclosure        provides crystallization using a second solvent, in one        embodiment with methyl tert-butyl ether (MTBE). In a further        embodiment, the present disclosure provides the crystalline        solid washed one or more times with acetonitrile. In a further        embodiment, the present disclosure provides the crystalline        solid dried under reduced pressure, including at a temperature        ranging from about 20.degree.C. to about 100.degree.C.

In another embodiment, the present disclosure provides a crystal form ofa compound of Formula I: ##STR00001 ##.

-   -   wherein Form I is described with the x-ray powder diffraction        pattern further comprises at least one peak selected from        22.3.+−0.0.3.degree., 25.3.+−0.0.3.degree., 5.4.+−0.0.3.degree.,        25.8.+−0.0.3.degree., 15.9.+−0.0.3.degree.,        29.9.+−0.0.3.degree., 21.6.+−0.0.3.degree., 16.5.+−0.0.3.degree.        and 20.3.degree. two theta.,    -   wherein greater than 90% by weight of the compound of Formula I:        ##STR00001 ## is Form I.

In another embodiment, the present disclosure provides a crystal form ofa compound of Formula I: ##STR00001 ##.

-   -   wherein the crystalline Form I, characterized by an x-ray powder        diffraction pattern further comprises at least one peak selected        from 22.3.+−0.0.3.degree., 25.3.+−0.0.3.degree.,        5.4.+−0.0.3.degree., 25.8.+−0.0.3.degree., 15.9.+−0.0.3.degree.,        29.9.+−0.0.3.degree., 21.6.+−0.0.3.degree., 16.5.+−0.0.3.degree.        and 20.3.degree. two theta.,    -   wherein greater than 90% by weight of the compound of Formula I:        ##STR00001 ## is Form I,    -   wherein the composition has an average diameter of less than        about 500 μm,    -   wherein the compound is stable for at least 12 months at        5.degree.C. and 60% relative humidity or at 25.degree.C. and 60%        relative humidity.

In another embodiment, the present disclosure provides methods of makingthe particulate delivery system of the compound of the composition,comprising: blending the composition together with an excipient to forma mixture; processing said mixture to form coarse particles having anaverage diameter ranging from about 0.1 mm to about 5 mm; and grindingor milling said coarse particles to form particles having an averagediameter less than about 0.5 mm. In a further embodiment, presentinvention also describes a method of making the particulate deliverysystem of the compound of the composition, comprising: blending thecomposition together with a polymer to form a mixture; processing saidmixture to form coarse particles having an average diameter ranging fromabout 0.1 mm to about 5 mm; and jet-milling said coarse particles toform particles having an average diameter less than about 1 micrometers.

In yet another embodiment, the present disclosure provides a particulatedelivery system comprising a crystalline form of a compound of FormulaI: ##STR00001 ##

-   -   wherein the crystalline Form I, characterized by an x-ray powder        diffraction pattern comprising major peaks at        22.3.+−0.0.3.degree., 25.3.+−0.0.3.degree., 5.4.+−0.0.3.degree.,        25.8.+−0.0.3.degree., 15.9.+−0.0.3.degree.,        29.9.+−0.0.3.degree., 21.6.+−0.0.3.degree., 16.5.+−0.0.3.degree.        and 20.3.degree. two theta. and at least one pharmaceutically        acceptable excipient,    -   wherein greater than 90% by weight of the compound of Formula I:        ##STR00001 ## is Form I,    -   wherein the composition has an average diameter of less than        about 500 μm,    -   wherein the compound is stable for at least 12 months at        5.degree.C. and 60% relative humidity or at 25.degree.C. and 60%        relative humidity,    -   and wherein the particulate delivery system is formulated for        oral delivery.

In yet another embodiment, the present disclosure provides anindustrially scalable process for manufacturing a crystalline form of acompound of Formula I: ##STR00001 ## and wherein the crystalline Form I,comprising the steps of:

-   -   reductive amination of methyl 2-aminothiophene-3-carboxylate        with sodium triacetoxyborohydride in anhydrous dichloromethane        and formic acid under argon followed by work up with potassium        hydroxide to obtain methyl        2-iso-propylaminothiophene-3-carboxylate,    -   acylation and cyclization of methyl        2-iso-propylaminothiophene-3-carboxylate in pyridine and        butyronitrile with methyl malonyl chloride followed by addition        of sodium methoxide solution to obtain methyl        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate,    -   amidation and of methyl        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate        with 3-piperidin-1-yl-propylamine, and acidification with        hydrochloric acid to obtain        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide hydrochloride,    -   preparation of        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine        carboxylic acid (3-piperidin-1-yl-propyl)-amide potassium salt        by adding 4-hydroxy        isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide hydrochloride, MTBE, water,        potassium hydroxide solution, and sodium bicarbonate to give        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine        carboxylic acid (3-piperidin-1-yl-propyl)-amide followed by        dissolution in acetonitrile and addition of potassium hydroxide        in water to give crystalline        4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic        acid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140        potassium salt),        whereas the crystalline form of a compound of Formula I:        ##STR00001 ## and wherein the crystalline form of Form I is        obtained by grinding the powder and sieving, wherein        crystallization is performed by cooling the solution to a        temperature ranging from about 0.degree.C. to about 20.degree.C.        for 2 to 4 hours., wherein the crystalline solid is dried under        reduced pressure at a temperature ranging from about        20.degree.C. to about 100.degree.C., wherein the crystalline        Form I is obtained by grinding the powder and sieving, and        wherein the crystalline form of a compound of Formula I:        ##STR00001 ## of Form I containing greater than 90% the desired        compound.

BRIEF DESCRIPTION OF THE FIGURES

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 is chemical structure of PRX-3140 (Formula I).

FIG. 2 shows the synthesis of crystalline fine particle Form I ofPRX-3140 potassium salt.

FIG. 3 is the XRD pattern of Form I of (A) Example 1 crystalline fineparticle Form I of PRX-3140 potassium salt and (B) crystalline fineparticle Form I of PRX-3140 potassium salt scale-up batch.

FIG. 4 shows the crystalline fine particle Form I of PRX-3140 potassiumsalt photostability study HPLC chromatograms as (A) unexposedcrystalline fine particle Form I of PRX-3140 potassium salt controlsample and (B) crystalline fine particle Form I of PRX-3140 potassiumsalt photostability exposed sample.

FIG. 5 shows the crystalline fine particle Form I of PRX-3140 potassiumsalt peroxide degradation products Formula II: ##STR00002 ##:5-hydroxy-8-(methylethyl)-8-hydro-1,2-oxathiino[6.5-b]pyridine-2,2,7-trione,or5-hydroxy-8-(propan-2-yl)-2H-2λ6-[1,2]oxathiino[6,5-b]pyridine-2,2,7(8H)-trioneand Formula III: ##STR00003 ##:[7-(methylethyl)1,4,6-trioxo(5,7-dihydrothiopheno[2,3-b]pyridine-5-yl)]-N-(3-piperidylpropyl)carboxamide,or1,4,6-trioxo-N-[3-(piperidin-1-yl)propyl]-7-(propan-2-yl)-4,5,6,7-tetrahydro-1H-1λ4-thieno[2,3-b]pyridine-5-carboxamide.

FIG. 6 is the Example 3 crystalline fine particle Form I of PRX-3140potassium salt forced degradation study (A) HPLC chromatogram ofstandard (Control) at 250 nm and (B) UV Spectra of Standard (Control) at12.2 minutes. Maxima are identified at 220, 250, and 320 nm.

FIG. 7 is the (A) LC-UV chromatogram of crystalline fine particle Form Iof PRX-3140 potassium salt Example 4 peroxide sample at 250 nm. Twomajor impurities at 9.6 and 13.3 minutes. (B) mass spectra of PRX-3140aperoxide sample at 9.6 minutes. [M+H]⁺ at 258.1 m/z, [M+H+NH3]⁺ at 275.1m/z, [M+Na]⁺ at 280.1 m/z and [2M+Na]⁺ at 537.1 m/z. (C) mass spectra ofPRX-3140b peroxide sample at 13.3 minutes. [M+H]+ at 394.2 m/z and[2M+H]+ at 787.4 m/z.

FIG. 8 is the 1H NMR of (A) the crude product of oxidation of PRX-3140and (B) unoxidized PRX-3140 potassium salt.

FIG. 9 is the (A) UV Chromatogram PRX-3140 30% Peroxide Sample at 250nm. (B) UV Spectra of Standard (Control) at 12.5 minutes. Maximums at220, 250, and 320 nm.

FIG. 10 is the (A) UV Spectra of PRX-3140a at 8.9 minutes. (B) UVSpectra of PRX-3140b at 12.9 minutes.

FIG. 11 is the (A) Mass Spectra at 12.5 min for Parent Molecule, [M+H]⁺at 378.2 m/z. (B) Mass Spectra at H₂O₂ Sample at 8.9 min and 70V. [M+H]+at 258.0 m/z, [M+H+NH3]+ at 275.1 m/z, [M+Na]+ at 280.1 m/z and [2M+Na]+at 537.1 m/z. (C) Mass Spectra at 12.9 min [M+H]+ at 394.2 m/z and[2M+H]+ at 787.4 m/z.

FIG. 12 is the HPLC chromatogram of PRX-3140: Lecithin (50:50) at (A)Time 0 initial sample and (B) 90 day sample, both at 250 nm.

DETAILED DESCRIPTION I. Terminology

Compounds are described using standard nomenclature. Unless definedotherwise, all technical and scientific terms used herein have the samemeaning as is commonly understood by one of skill in the art to whichthis invention belongs.

The terms “a” and “an” do not denote a limitation of quantity, butrather denote the presence of at least one of the referenced items. Theterm “or” means “and/or”. The terms “comprising,” “having,” “including,”and “containing” are to be construed as open-ended terms (i.e., meaning“including, but not limited to”).

Recitation of ranges of values are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein, and eachseparate value is incorporated into the specification as if it wereindividually recited herein. The endpoints of all ranges are includedwithin the range and independently combinable.

All methods described herein can be performed in a suitable order unlessotherwise indicated herein or otherwise clearly contradicted by context.The use of any and all examples, or exemplary language (e.g., “suchas”), is intended merely to better illustrate the invention and does notpose a limitation on the scope of the invention unless otherwiseclaimed. No language in the specification should be construed asindicating any non-claimed element as essential to the practice of theinvention as used herein. Unless defined otherwise, technical, andscientific terms used herein have the same meaning as is commonlyunderstood by one of skill in the art of this disclosure.

Furthermore, the disclosure encompasses all variations, combinations,and permutations in which one or more limitations, elements, clauses,and descriptive terms from one or more of the listed claims areintroduced into another claim. For example, any claim that is dependenton another claim can be modified to include one or more limitationsfound in any other claim that is dependent on the same base claim. Whereelements are presented as lists, e.g., in Markush group format, eachsubgroup of the elements is also disclosed, and any element(s) can beremoved from the group.

All compounds are understood to include all possible isotopes of atomsoccurring in the compounds. Isotopes include those atoms having the sameatomic number but different mass numbers. By way of general example, andwithout limitation, isotopes of hydrogen include tritium and deuteriumand isotopes of carbon include .sup.11C, .sup.13C, and .sup.14C.

The opened ended term “comprising” includes the intermediate and closedterms “consisting essentially of” and “consisting of.”

A significant change is any detectable change that is statisticallysignificant in a standard parametric test of statistical significancesuch as Student's T-test, where p<0.05.

II. Synthesis of Crystalline Fine Particle Form I of PRX-3140 PotassiumSalt

The disclosure includes the following embodiments, which should not beconstrued as limiting. Rather, these embodiments are exemplary and areprovided to describe the invention to those skilled in the art. Likereference numerals refer to like elements throughout.

It has been unexpectedly discovered that dissolution of4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide free base in acetonitrile andaddition of potassium hydroxide in water may be used to obtaincrystalline4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140 potassiumsalt) by heating followed by cooling. This process is distinct from theusual crystallization procedure from U.S. Pat. Nos. 7,488,736 and7,982,040, which uses potassium tert-butoxide in water mixed withdichloromethane and ethyl acetate, and unexpectedly provides acrystalline solid containing greater than 90% the desired4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140 potassiumsalt).

In one aspect, the present disclosure provides an industrially scalableprocess for manufacturing PRX-3140 potassium salts thereof, comprisingthe steps of: (A) reductive amination of methyl2-aminothiophene-3-carboxylate with 2,2-dimethoxypropane using sodiumtriacetoxyborohydride in anhydrous dichloromethane and formic acid underargon followed by work up with potassium hydroxide to obtain methyl2-iso-propylaminothiophene-3-carboxylate (3), (B) acylation andcyclization of methyl 2-iso-propylaminothiophene-3-carboxylate (3) inpyridine and butyronitrile with methyl malonyl chloride followed byaddition of sodium methoxide solution to obtain methyl4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate(5), (C) amidation of methyl4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate(5) with 3-piperidin-1-yl-propylamine (6), and acidification of theresulting crude PRX-3140 with hydrochloric acid to obtain4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide hydrochloride (8), and (D)preparation of4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide potassium salt by adding4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide hydrochloride (8), MTBE, water,potassium hydroxide solution, and sodium bicarbonate to give4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide to obtain the free base followed bydissolution in acetonitrile and addition of potassium hydroxide in waterto give crystalline4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140 potassiumsalt). The crystalline fine particle Form I of PRX-3140 potassium saltis obtained by grinding the powder and sieving.

The initial step in the disclosed process is the crystallizing of aninput4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide free base and acetonitrile andaddition of potassium hydroxide in water to provide crystalline4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140 potassiumsalt) solid and a mother liquor followed by drying, wherein thecrystalline solid containing greater than 90% the desired PRX-3140potassium salt. The crystallization can be performed by dissolving theinput free base in acetonitrile at a first temperature by heating andthen cooling the solution to a second temperature to effectcrystallization. The solution can be held at the second temperature forseveral hours to allow for adequate crystallization. For example, theinput free base can be dissolved in acetonitrile at 45 to 50.degree.C.,and then the resulting solution is cooled to 0 to 5.degree.C., and heldat the second temperature for 0.5 hours to 10 days, preferably 2 to 4hours. In some cases, longer holding times at the second temperature maybe required. The crystalline solid and the mother liquor may beseparated by filtration, decanting, aspiration, or any suitable method.The separated crystalline solid may be washed with a suitable solvent toremove impurities and can be dried with or without heat and/or reducedpressure to remove solvent. Preferably, the crystalline solid iscollected by filtration, washed with solvent, and dried in vacuo toconstant weight. The separated mother liquor can be concentrated invacuo to give a solid or a non-solid and can be dried with or withoutheat and/or reduced pressure to remove solvent. Preferably, theconcentrated mother liquor is dried in vacuo to constant weight.

It has been unexpectedly discovered that acetonitrile is a particularlyuseful solvent for carrying out this step. Other solvents, such as MTBE,may also be used as the second solvent. The crystallization can beperformed by dissolving the input crystalline solid in the secondsolvent at a first temperature of 20 to 100.degree.C. and then coolingthe solution by 20 to 100.degree.C. to a second temperature to effectcrystallization. The solution can be held at the second temperature forseveral hours to allow for adequate crystallization. For example, asolid formed from the concentrated first mother liquor can be dissolvedin acetonitrile from 30 to 70.degree.C., preferably from 40 to60.degree.C., and then the resulting solution is cooled to −10 to20.degree.C. or 0 to 10.degree.C., and held at the second temperaturefor 0.5 hours to 10 days or 2 to 72 hours. In some cases, longer holdingtimes at the second temperature may be required. The crystalline solidand the mother liquor may be separated by filtration, decanting,aspiration, or any suitable method. The separated crystalline solid maybe washed with a suitable solvent to remove impurities and can be driedwith or without heat and/or reduced pressure to remove solvent. Theseparated mother liquor can be concentrated in vacuo to give a solid andcan be dried with or without heat and/or reduced pressure to removesolvent. Preferably, the mother liquor is separated from the crystallinesolid by aspiration, concentrated and dried in vacuo to constant weight.

III. Crystalline Forms

In certain aspects, the present disclosure provides crystalline fineparticle Form I of PRX-3140 potassium salt. The present disclosurefurther provides pharmaceutical compositions of PRX-3140 potassium saltcomprising the crystalline forms described herein. A crystalline form ofPRX-3140 potassium salt may provide the advantage of bioavailability andstability, suitable for use as an active ingredient in a pharmaceuticalcomposition. Variations in the crystal structure of a pharmaceuticaldrug substance or active ingredient may affect the dissolution rate(which may affect bioavailability, etc.), manufacturability (e.g., easeof handling, ability to consistently prepare doses of known strength)and stability (e.g., thermal stability, shelf life, etc.) of apharmaceutical drug product or active ingredient. Such variations mayaffect the preparation or formulation of pharmaceutical compositions indifferent dosage or delivery forms, such as solid oral dosage formsincluding tablets and capsules. Compared to other forms such asnon-crystalline or amorphous forms, crystalline forms may providedesired or suitable hygroscopicity, particle size controls, dissolutionrate, solubility, purity, physical and chemical stability,manufacturability, yield, and/or process control. Thus, crystallineforms of PRX-3140 potassium salt may provide advantages such as:improving the manufacturing process of an active agent or the stabilityor storability of a drug product form of the compound or an activeingredient, and/or having suitable bioavailability and/or stability asan active agent.

The use of certain solvents and fractional crystallization methods hasbeen found to produce different polymorphic forms of PRX-3140 potassiumsalt, including polymorphic Form I, which may exhibit one or morefavorable characteristics described above. The processes for thepreparation of the polymorphs described herein, and characterization ofthese polymorphs are described in greater detail below.

In certain aspects, the present disclosure provides polymorphic Form Iof PRX-3140 potassium salt, wherein at least 90% by weight is PRX-3140potassium salt. In some embodiments, polymorphic Form I exhibits anx-ray diffraction (XRD) pattern substantially as shown in FIG. 3 . Insome embodiments, polymorphic Form I has an XRD pattern comprising atleast two, at least three, at least four, at least five, or at least sixof the major peaks as the XRD pattern substantially as shown in FIG. 3 .The crystalline structure of the present invention is substantiallypure, unitary, and substantially free of any other crystal form oramorphous state. “Substantially pure” in the present invention when usedin reference to a new crystal form means that this new crystal formcomprises at least 80% (by weight) of the present compound, morepreferably at least 90% (by weight), and especially at least 95% (byweight), especially at least 99% (by weight).

The term “substantially as shown in” when referring, for example, to anXRD pattern, includes a pattern that is not necessarily identical tothose depicted herein, but that falls within the limits of experimentalerror or deviations when considered by one of ordinary skill in the art.The relative intensities of XRD peaks can vary, depending upon theparticle size, the sample preparation technique, the sample mountingprocedure and the particular instrument employed. The crystalline formin the present invention means that the compound is confirmed by theX-ray powder diffraction pattern characterization shown and has a uniqueand ordered molecular arrangement or configuration within the crystallattice. It is well known to those skilled in the art that theexperimental error depends on the instrument conditions, samplepreparation and sample purity. The 2.theta. angle of the peaks in theXRD pattern usually varies slightly depending on the instrument andsample. The difference in peak angle may differ by 1.degree.,0.8.degree., 0.5.degree., 0.3.degree., 0.1.degree., etc. according todifferent instruments, different samples, etc. Generally, the toleranceis .+−0.0.2.degree. Therefore, the difference in peak angle cannot beused as the sole criterion. The relative intensity of peaks may varywith samples, sample preparation, and other experimental conditions, sothe order of peak intensities cannot be the sole or decisive factor. Theinfluence of experimental factors such as sample height will cause theoverall shift of the peak angle, which usually allows a certain shift.Therefore, those skilled in the art can understand that any crystal formhaving the same or similar characteristic peaks as the X-ray powderdiffraction pattern of the present invention belongs to the scope of thepresent invention. “Single crystalline form” refers to a single crystalform as determined by X-ray powder diffraction.

Moreover, instrument variation and other factors can affect the twotheta (2.theta.) values. Accordingly, when a specified two theta angleis provided, it is to be understood that the specified two theta anglecan vary by the specified value .+−0.0.5.degree., such as.+−0.0.4.degree., +0.3.degree., .+−0.0.2.degree., or .+−0.0.1.degree. Asused herein, “major peak” refers to an XRD peak with a peak intensitygreater than baseline, such as greater than 100 or 500 depending on thebaseline noise and other test factors listed above.

In certain aspects, the present disclosure provides at least 90% byweight of PRX-3140 compound of Formula I in the composition is acrystalline form of the potassium salt. Crystalline Form I may becharacterized by an x-ray powder diffraction pattern comprising majorpeaks at 22.3.+−0.0.3.degree., 25.3.+−0.0.3.degree. and5.4.+−0.0.3.degree. two theta, and optionally further comprising atleast one peak selected from 25.8.+−0.0.3.degree., 15.9.+−0.0.3.degree.and 29.9.+−0.0.3.degree. two theta. In some embodiments, the x-raypowder diffraction pattern further comprises at least one peak selectedfrom 21.6.+−0.0.3.degree., 16.5.+−0.0.3.degree. and 20.3.degree. twotheta. The x-ray powder diffraction pattern may further comprise peaksat 21.3.+−0.0.3.degree., 17.1.+−0.0.3.degree., 16.3.+−0.0.3.degree.,33.1.+−0.0.3.degree., 45.6.+−0.0.3.degree. and 13.7.+−0.0.3.degree. twotheta. In some embodiments, crystalline Form I is characterized by anx-ray powder diffraction pattern substantially as set forth in FIG. 3 .Greater than 90%, 95% or 99% by weight of the compound of Formula I inthe composition may be crystalline Form I. In some embodiments, thecomposition comprises 0.01 mg to 200 mg of crystalline Form I, such asabout 10 mg, 25 mg, 50 mg, 75 mg, 100 mg or 200 mg of crystalline Form I

In some embodiments, a composition comprising crystalline form ofPRX-3140 potassium salt comprises 0.01%, 0.05%, 0.01%, 0.1%, 0.2%, 0.3%,0.4%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%,15%, 16%, 17%, 18%, 19% or 20% PRX-3140 potassium salt (wt/wt) or (w/v)of the composition. In some embodiments, a composition comprisingcrystalline form of PRX-3140 potassium salt comprises 0.01%, 0.05%,0.01%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%,10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20% PRX-3140potassium salt (wt/wt) or (w/v) of the composition.

The compounds and compositions of the present disclosure can beadministered to a subject in need thereof by any route known in the art,including without limitation, oral, parenteral, topical, and intraductaldelivery. Accordingly, compositions disclosed herein are formulated tobe compatible with the intended route of administration.

In some embodiments, the compositions comprising crystalline form ofPRX-3140 potassium salt further comprise an excipient. Such an excipientcan be compatible with the intended route of administration.

IV. Methods of Making a Particle Delivery System (PDS)

The present disclosure also provides a method of making a composition ofthe present disclosure comprising particles of the crystalline form ofPRX-3140 potassium salt encapsulated by an excipient, the methodcomprising:

-   -   blending crystalline form of PRX-3140 potassium salt together        with an excipient to form a mixture;    -   processing said mixture to form coarse particles having an        average diameter ranging from about 0.1 mm to about 5 mm; and    -   grinding or milling said coarse particles to form particles        having an average diameter less than about 500 micrometers.

In certain embodiments, the particles have an average diameter rangingfrom about 0.1 microns to about 0.1 mm. Particulate materials, alsodesignated as “particles”, to be produced in accordance with thisdisclosure are those in which small nanometer to micrometer sizeparticles may be desirable. Examples may include nanoparticles andmicroparticle forms of pharmaceuticals, including crystalline form ofPRX-3140 potassium salt. The possibilities and combinations arenumerous.

In one embodiment, a system for preparing a composition of the presentdisclosure may include a grinding the crystalline form of PRX-3140potassium salt in a mortar and pestle or with a ball mill. In anotherembodiment a system for preparing a composition of the presentdisclosure may include a venturi-type nozzle or ‘Tee’ valve to introducecryogenic gas to, for example, a jet mill. Without wishing to be boundby any particular theory, combinations of dry gases at cryogenictemperatures (generally below 0.degree.C) before introduction into thejet mill may be used to eliminate moisture-induced agglomeration, aswell as promote brittle fracture of particles upon impaction, and hasbeen observed to act synergistically to produce a marked improvement inthe particle size reduction efficiency. Cryogenic liquids suitable foruse in this method include liquid argon, liquid nitrogen, liquid heliumor any other liquified gas having a temperature sufficiently low toproduce brittle fracture of particles. The cryogenic liquid may alsoprevent milling losses and thermal damage to the feed material thatwould otherwise be caused by the volatization or overheating ofconstituent ingredients.

In one embodiment, a powder is placed in a temperature-controlledvessel, such as a jacketed hopper or a screw-feeder or is frozenbeforehand. The cryogenic liquid and gas inputs are opened, and the flowand temperature are set to the desired process conditions. The cryogenicgas input system, for example liquid nitrogen mixed with nitrogen gas,may be connected to a standard commercial jet mill, such as a TrostGem-T, Trost T-15, Fluid Air Alj et, Hosikawa Alpine AS Spiral Jet Mill,Sturtevant Micronizer, or similar system, as the main carrier gas in avariety of gas input setups. Pre-run setup of the system may includeattaching a temperature probe or flowmeter, such as a TSI Model 4040Flowmeter or similar system, at the gas input or to the top of thecyclone (in place of air relief bag), setting the carrier gas ondifferent input pressures and documenting the gas flow and temperaturemeasurements (CFM). The milling process may be started by turning on thepowder feeder and after passing powder through the milling region, thejet-milled powder is collected in the cup or similar receiver unit(typically particles ˜1-10 microns) or from the bag above the cyclone(particles <1 micron), depending on the exact run conditions. Particleswith diameters ranging from less than about 1 micron to about 10 micronsmay be produced by running the powder from the cup through the jet-millunder similar run conditions multiple times, or passes, to obtain thedesired particle size.

In certain embodiments, the particles may have an average diameterranging from about 0.1 mm (100 microns) to about 3 mm. For example, theparticles may have a diameter of less than about 2.06 mm (correspondingto a 10 mesh sieve), less than about 1.68 mm (corresponding to a 12 meshsieve), less than about 1.40 mm (corresponding to a 14 mesh sieve), lessthan about 1.20 mm (corresponding to a 16 mesh sieve), less than about1.00 mm (corresponding to an 18 mesh sieve), less than about 0.853 mm(corresponding to a 20 mesh sieve), less than about 0.710 mm(corresponding to a 25 mesh sieve), less than about 0.599 mm(corresponding to a 30 mesh sieve), or less than about 0.500 mm(corresponding to a 35 mesh sieve). In some embodiments, the particlesmay have a diameter of less than about 300 microns and may be able topass through a 50-mesh sieve. In certain embodiments, the particles havea diameter of about 0.6 mm or less.

In certain embodiments, the controlled-release polymer is heated priorto blending with the crystalline form of PRX-3140 potassium salt.

In some embodiments, the present disclosure provides a method of makinga composition of the present disclosure comprising particles of thecrystalline form of PRX-3140 potassium salt encapsulated by acontrolled-release polymer using a process wherein the process is atleast partially a continuous manufacturing process. The method maycomprise:

-   -   blending the crystalline form of PRX-3140 potassium salt        together with a controlled-release polymer to form a mixture;    -   heating said mixture to a temperature sufficient for extrusion        of the mixture;    -   extruding said mixture to form coarse particles having an        average diameter ranging from about 0.1 mm to about 5 mm;    -   cooling said coarse particles; and    -   processing (e.g., by milling, grinding, or crushing) said coarse        particles to form particles having an average diameter less than        about 0.1 mm.

In certain embodiments, the particles may have an average diameterranging from about 0.1 mm (100 microns) to about 3 mm. For example, theparticles may have a diameter of less than about 2.06 mm (correspondingto a 10 mesh sieve), less than about 1.68 mm (corresponding to a 12 meshsieve), less than about 1.40 mm (corresponding to a 14 mesh sieve), lessthan about 1.20 mm (corresponding to a 16 mesh sieve), less than about1.00 mm (corresponding to an 18 mesh sieve), less than about 0.853 mm(corresponding to a 20 mesh sieve), less than about 0.710 mm(corresponding to a 25 mesh sieve), less than about 0.599 mm(corresponding to a 30 mesh sieve), or less than about 0.500 mm(corresponding to a 35 mesh sieve). In some embodiments, the particlesmay have a diameter of less than about 300 microns and may be able topass through a 50 mesh sieve. In certain embodiments, the particles mayhave a diameter of about 0.1 mm or less.

In certain embodiments, the controlled-release polymer may be heatedprior to blending with the crystalline form of PRX-3140 potassium salt.

V. Pharmaceutical Compositions (Final Dosage Forms)

The present disclosure further provides pharmaceutical compositions(sometimes referred to as “final dosage forms” or “FDF”) comprisingcompositions according to the present disclosure.

In some embodiments, the pharmaceutical compositions may furthercomprise at least one excipient (such as, e.g., a controlled-releasepolymer, surfactant, and/or metal salt), such as a pharmaceuticallyacceptable excipient. Examples of pharmaceutically acceptable excipientsmay be, for example, those described in Remington's PharmaceuticalSciences by E. W. Martin, and include cellulose, starch, glucose,lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodiumstearate, glycerol monostearate, talc, sodium chloride, dried skim milk,glycerol, propylene glycol, water, ethanol, and the like. In someembodiments, the pharmaceutical compositions also contain pH bufferingreagents, and wetting or emulsifying agents.

In some embodiments, the pharmaceutical compositions may be formulatedfor oral administration. In this embodiment, the pharmaceuticalcomposition may be in the form of, for example, tablets, capsules, orother oral dosage forms. Such oral dosage forms may be prepared byconventional means. The pharmaceutical composition can also be preparedas a liquid, for example as a syrup or a suspension. The liquid caninclude suspending agents (e.g., sorbitol syrup, cellulose derivatives,or hydrogenated edible fats), emulsifying agents (lecithin or acacia),non-aqueous vehicles (e.g., almond oil, oily esters, ethyl alcohol, orfractionated vegetable oils), and preservatives (e.g., methyl orpropyl-p-hydroxybenzoates or sorbic acid). The preparations can alsoinclude flavoring, coloring, and sweetening agents. Alternatively, thecomposition can be presented as a dry product for constitution withwater or another suitable vehicle.

For buccal and sublingual administration, the composition may take theform of tablets or lozenges according to conventional protocols.

The pharmaceutical composition can also be formulated for rectaladministration as a suppository or retention enema, e.g., containingconventional suppository bases such as PEG, cocoa butter, or otherglycerides.

In some embodiments, the pharmaceutical compositions described hereinprovide improved dissolution of the crystalline form of PRX-3140potassium salt, relative to the unencapsulated crystalline form ofPRX-3140 potassium salt, and/or to another dosage form (such as, e.g., amore invasive dosage form). For example, dissolution may be increasedby, e.g., at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%,80%, 90%, 93%, 95%, 96%, 97%, 98%, 99%, 100%, 110%, 120%, 130%, 140%,150%, or 200%, or by, e.g., at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30,40, 50, 100, or 1000 fold, as measured by a Vankel tablet dissolutionapparatus approved by the United States Pharmacopeia.

In some embodiments, the pharmaceutical compositions described hereinprovide improved oral bioavailability of the crystalline form ofPRX-3140 potassium salt, relative to the unencapsulated crystalline formof PRX-3140 potassium salt, and/or to another dosage form (such as,e.g., a more invasive dosage form). For example, absorption may beincreased by, e.g., at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%,60%, 70%, 80%, 90%, 93%, 95%, 96%, 97%, 98%, 99%, 100%, 110%, 120%,130%, 140%, 150%, or 200%, or by, e.g., at least 2, 3, 4, 5, 6, 7, 8, 9,10, 20, 30, 40, 50, 100, or 1000 fold, as measured by, e.g., in vivopharmacokinetic studies in a preclinical animal model or human clinicalevaluation.

In some embodiments, the pharmaceutical compositions described hereinare immediate-release formulations. In such embodiments, thepharmaceutical compositions provide a more rapid onset of action of thecrystalline form of PRX-3140 potassium salt, relative to theunencapsulated crystalline form of PRX-3140 potassium salt, and/or toanother dosage form (such as, e.g., a more invasive dosage form). Forexample, the onset of action may be shortened by, e.g., at least 10%,15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80%, 90%, 93%, 95%, 96%,97%, 98%, 99%, 100%, 110%, 120%, 130%, 140%, 150%, or 200%, or by, e.g.,at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, or 1000 fold,as measured by, e.g., in vivo pharmacokinetic studies in a preclinicalanimal model or human clinical evaluation.

In some embodiments, the pharmaceutical compositions described hereinare controlled-release formulations. In such embodiments, thepharmaceutical compositions described herein provide a more rapid onsetof action of the crystalline form of PRX-3140 potassium salt.

In some embodiments, the pharmaceutical compositions described hereinhave reduced absorption variability, relative to the unencapsulatedinsoluble drug, and/or to another dosage form (such as, e.g., a moreinvasive dosage form).

In some embodiments, the pharmaceutical compositions described hereinare associated with improved patient compliance, relative to anotherpharmaceutical composition comprising the crystalline form of PRX-3140potassium salt (which may be in another dosage form, such as, e.g., amore invasive dosage form).

In some embodiments, a pharmaceutical composition of the presentdisclosure is formulated for oral delivery. Compositions intended fororal use may be prepared in solid or fluid unit dosage forms. In atleast some embodiments, the compositions are formulated for oraldelivery as tablets, caplets, capsules, pills, powders, troches,elixirs, suspensions, syrups, wafers, chewing gums, dragees, lozenges,and the like.

In some embodiments, the oral dosage forms are solid oral dosage formssuch as tablets, caplets, and capsules. In some embodiments, the capsuleis a hard capsule or a soft capsule. In other embodiments, the capsuleis a gelatin capsule, gelatin-free capsule, a “cap-in-cap” capsule,alginate capsule, hydroxypropylmethyl cellulose (HPMC) capsule, apolyvinyl alcohol (PVA) capsule, a hypromellose capsule, or a starchcapsule.

In some embodiments, an oral composition comprising the crystalline formof PRX-3140 potassium salt thereof further comprises one or moreexcipients. In some embodiments, an oral composition comprising thecrystalline form of PRX-3140 potassium salt or a polymorph thereoffurther comprises one or more excipients. Accordingly, compositionsdesigned for oral administration can be made with an inert or activeexcipient or with an edible carrier as disclosed herein.

In various embodiments, the composition provided herein comprises fromabout 1% to about 99.99%, about 5% to about 95%, about 5% to about 90%,about 10% to about 80%, about 15% to about 70%, about 20% to about 60%,from about 30% to about 95%, from about 50% to about 90%, from about 60%to about 90%, from about 60% to about 80%, or from about 70% to about80% by weight of one or more excipients. In certain embodiments, thecomposition provided herein comprises about 99.99%, about 95%, about90%, about 85%, about 80%, about 75%, about 70%, about 65%, about 60%,about 55%, or about 50% by weight of one or more excipients. In certainembodiments, the composition provided herein comprises about 99.99%,about 99%, about 98%, about 97%, about 96%, about 95%, about 94%, about93%, about 92%, about 91%, about 90%, about 89%, about 88%, about 87%,about 86%, or about 85% by weight of one or more excipients. In certainembodiments, the composition provided herein comprises about 85%, about84%, about 83%, about 82%, about 80%, about 79%, about 78%, about 77%,about 76%, about 75%, about 74%, about 73%, about 72%, about 71%, about70%, about 69%, about 68%, about 67%, about 66%, or about 65% by weightof one or more excipients. In certain embodiments, the compositionprovided herein comprises about 55%, about 54%, about 53%, about 52%,about 51%, about 50%, about 49%, about 48%, about 47%, about 46%, orabout 45% by weight of one or more excipients. In certain embodiments,the composition provided herein comprises about 30%, about 29%, about28%, about 27%, about 26%, about 25%, about 24%, about 23%, about 22%,about 21%, or about 20% by weight of one or more excipients.

Examples of excipients that can be used in the compositions formulatedfor oral administration are provided herein and can include, but are notlimited to, one or more of bulking agents, binders, fillers,disintegrating agents, lubricants, glidants, control release agents,enteric coatings, film-forming agents, plasticizers, colorants,sweetners, flavoring agents and the like, or any combination thereof.

Binders suitable for use in the pharmaceutical compositions providedherein include, but are not limited to, sucrose, starches such as cornstarch, potato starch, or starches such as starch paste, pregelatinizedstarch, and starch 1500, PEG 6000, methocel, walocel HM, Luvitec,Luvicaparolactam, Avicel, SMCC, UNIPURE, gelatin, natural and syntheticgums such as acacia, sodium alginate, alginic acid, other alginates,tragacanth, guar gum, cellulose and its derivatives (e.g., ethylcellulose, cellulose acetate, carboxymethyl cellulose calcium, sodiumcarboxymethyl cellulose), polyvinyl pyrrolidone, methyl cellulose,polyvinyl pyrrolidone, hydroxypropyl methyl cellulose, (e.g., Nos 2208,2906, 2910), microcrystalline cellulose, and mixtures thereof. Suitableforms of microcrystalline cellulose include, but are not limited to, thematerials sold as AVICEL PH 101, AVICEL PH 103 AVICEL RC 581, AVICEL PH105 (available from FMC Corporation, American Viscose Division, AvicelSales, Marcus Hook, Pa.), and mixtures thereof. In some embodiments, thebinder is a mixture of microcrystalline cellulose and sodiumcarboxymethyl cellulose. Suitable anhydrous or low moisture excipientsor additives include AVICEL PH 103 and Starch 1500 LM.

Examples of fillers suitable for use in the pharmaceutical compositionsprovided herein include, but are not limited to, talc, calcium carbonate(e.g., granules or powder), sugars such as dextrose, sucrose, lactose, asalt such as calcium carbonate, calcium phosphate, sodium carbonate,sodium phosphate, starches, microcrystalline cellulose, powderedcellulose, cellulosic bases such as methyl cellulose, carboxymethylcellulose dextrates, kaolin, mannitol, silicic acid, sorbitol, starch,pregelatinized starch, and mixtures thereof.

One or more binder or filler in compositions is typically present infrom about 10% to about 99% (wt/wt) of the composition or the dosageform. In some embodiments, binders and/or fillers in a compositioncomprise about 15% to 99%, about 20% to 60%, about 25% to 55%, about 30%to 50%, about 35% to 60%, about 50% to 99% (wt/wt) of the composition.

Disintegrants can be used in the compositions to provide tablets thatdisintegrate when exposed to an aqueous environment. Tablets thatcontain too much disintegrant may disintegrate in storage, while thosethat contain too little may not disintegrate at a desired rate or underthe desired conditions. Thus, a sufficient amount of disintegrant thatis neither too much nor too little to detrimentally alter the release ofthe active ingredients should be used to form solid oral dosage forms.In some embodiments, the disintegrant is deep in the oral solid dosageform to delay disintegration. The amount of disintegrant used variesbased upon the type of formulation, and is readily discernible to thoseof ordinary skill in the art.

Typical compositions comprise from 0.5% to 15% (wt/wt) of disintegrant.In some embodiments, compositions comprise from 1% to 5% (wt/wt) ofdisintegrant in the composition. In another embodiment, the disintegrantis 1% to 25%, 2% to 20%, 5% to 15%, 8% to 12%, or about 10% (wt/wt) ofthe composition.

Disintegrants that can be used in the pharmaceutical compositionsprovided herein include, but are not limited to, agar, alginic acid,calcium carbonate, microcrystalline cellulose, croscarmellose sodium,crospovidone, polacrilin potassium, sodium starch glycolate, potato ortapioca starch, pre-gelatinized starch, other starches, clays, otheralgins, other celluloses, gums, and mixtures thereof.

Lubricants that can be used in the pharmaceutical compositions providedherein include, but are not limited to, calcium stearate, magnesiumstearate, mineral oil, light mineral oil, glycerin, sorbitol, mannitol,polyethylene glycol, other glycols, stearic acid, sodium lauryl sulfate,talc, hydrogenated vegetable oil (e.g., peanut oil, cottonseed oil,sunflower oil, sesame oil, olive oil, corn oil, and soybean oil), zincstearate, magnesium stearate or potassium stearate, ethyl oleate, ethyllaureate, agar, and mixtures thereof. Additional lubricants include, forexample, a syloid silica gel (AEROSIL 200, manufactured by W.R. GraceCo. of Baltimore, Md.), a coagulated aerosol of synthetic silica(marketed by Degussa Co. of Plano, Tex.), CAB O SIL (a pyrogenic silicondioxide product sold by Cabot Co. of Boston, Mass.), Q7-9120 (DowCorning), and mixtures thereof. If used at all, lubricants are typicallyused in an amount of less than 1% (wt/wt) of the compositions or dosageforms into which they are incorporated. In yet another embodiment, thelubricant is 0.1% to 3%, such as 0.5% to 1% (wt/wt), of the composition.

Plasticizers may be added to control the softness or pliability of oraldosage forms such as shell of a capsule, caplet or a tablet and thus,may improve the mechanical properties of the pH-sensitive materials ofthe coatings on the oral dosage forms. Suitable plasticizers, include,without limitation, petroleum oils (for e.g., a paraffinic process oil,a naphthenic process oil, and an aromatic process oil), squalene,squalane, plant oils, (e.g., olive oil, camelia oil, castor oil, talloil, and a peanut oil), silicon oils, dibasic acid esters, (e.g.,dibutyl phthalate, and dioctyl phthalate), liquid rubbers (e.g.,polybutene and a liquid isoprene rubber), liquid fatty acid esters(e.g., isopropyl myristate ISM), hexyl laurate, diethyl sebacate, anddiisopropyl sebacate, triethyl citrate, triacetin, diethylene glycol,polyethylene glycols, polypropylene glycol, phthalates, sorbitol, glycolsalicylate, crotaminton, and glycerin or mixtures thereof. The amount ofplasticizer may vary depending upon the chemical composition of thepharmaceutical preparation. In one embodiment, the at least oneplasticizer is sorbitol, dimethyl isosorbide, or a glycerol. In anotherembodiment, the plasticizer is 1% to 10%, such as 3% to 5% (wt/wt), ofthe composition.

Examples of glidants include, but are not limited to, colloidal siliconedioxide, cellulose, calcium phosphate, di or tri-basic and the like.

As an example of sweeteners or sweetening agents include sucrose,saccharin, dextrose, maltose, sugar substitutes, aspartame, xylitol,mannitol, cyclamate, sucralose, maltitol, sorbitol, acesulfame K and thelike.

Examples of flavoring agents include peppermint, methyl salicylate,peppermint, spearmint, methyl salicylate, raspberry, red berry,strawberry, pineapple, orange, cherry and the like.

Compositions formulated for oral delivery as disclosed herein, forexample, tablets, caplets, and capsules, may be coated with one or moreenteric coating agent, control release agent or film forming agent tocontrol or delay disintegration and absorption of the compositionscomprising the crystalline form of the compound of Formula I thereof inthe gastrointestinal tract and thereby provide a sustained action over alonger period of time. Accordingly, in some embodiments, the tablet canbe an enteric tablet, the caplet can be an enteric caplet, or thecapsule can be an enteric capsule. The enteric tablets, enteric caplets,or enteric capsules of the present disclosure may be prepared bytechniques known in the art.

Pharmaceutical preparations disclosed herein may comprise a controlrelease agent. Examples of control release agent suitable for useinclude, without limitation, pH-dependent polymers, acid-insolublepolymers, methyl acrylate-methacrylic acid copolymers, cellulose acetatephthalate (CAP), cellulose acetate succinate, hydroxypropyl methylcellulose phthalate, hydroxypropyl methyl cellulose acetate succinate(hypromellose acetate succinate), polyvinyl acetate phthalate (PVAP),methyl methacrylate-methacrylic acid copolymers, shellac, celluloseacetate trimellitate, sodium alginate, zein, waxes, including syntheticwaxes, microcrystalline waxes, paraffin wax, carnauba wax, and beeswax;polyethoxylated castor oil derivatives, hydrogenated oils, glycerylmono-, di-tribenates, glyceryl monostearate, glyceryl distearate, longchain alcohols, such as stearyl alcohol, cetyl alcohol, and polyethyleneglycol; and mixtures thereof. In some embodiments, a time delay materialsuch as glyceryl monostearate or glyceryl distearate may be used. Inother embodiments, the controlled release reagent is a digestible waxysubstance such as hard paraffin wax.

In some embodiments, compositions may comprise one or more ofpH-dependent polymers such as acid insoluble polymers. The pH-dependentpolymers become increasingly permeable above pH 5.0 but are impermeableat pH below 5.0 whereas acid insoluble polymers become soluble inneutral to weakly alkaline conditions. Such control release polymerstarget upper small intestines and colon. Non-limiting examples ofacid-insoluble polymers include cellulose acetate phthalate, celluloseacetate butyrate, hydroxypropyl methyl cellulose phthalate, algenic acidsalts such as sodium or potassium alginate, shellac, pectin, acrylicacid-methylacrylic acid copolymers (commercially available under thetradename EUDRAGIT® L and EUDRAGIT® S from Rohm America Inc.,Piscataway, N.J. as a powder or a 30% aqueous dispersion; or under thetradename EASTACRYL®, from Eastman Chemical Co., Kingsport, Tenn., as a30% dispersion). Additional examples include EUDRAGIT® L100-55,EUDRAGIT® L30D-55, EUDRAGIT® L100, EUDRAGIT® L100 12,5, EUDRAGIT® 5100,EUDRAGIT® 512,5, EUDRAGIT® FS 30D, EUDRAGIT® E100, EUDRAGIT® E 12,5, andEUDRAGIT® PO. In at least one embodiment, the composition comprisesEUDRAGIT® L100-55. EUDRAGIT® RS and RL and EUDRAGIT® NE and NM are alsouseful polymers for the purpose of this disclosure. In some embodiments,the composition comprises EUDRAGIT® L30D 55. In another embodiment, thepreparation comprises EUDRAGIT® FS 30D. One of skill in the art willrecognize that at least some acid insoluble polymers listed herein willalso be biodegradable.

For time delay or delayed-release pharmaceutical preparations of oraldosage forms, glyceryl monostearate, glyceryl distearate, andacid-insoluble polymers, for example polymethacrylate pH-sensitivepolymer-based coatings can be used, (e.g., as coating material, i.e.,enteric coating agents, for enteric coating of capsules, caplets, andtablets). Commercial sources for delayed-release oral dosage forms areavailable, for example DRCaps made of hypromellose (HPMC) from Capsugel,USA. Such delayed-release oral dosage forms are acid-resistant and canresist acidity as seen in stomach for at least 30 min, such as for atleast 1 hour, for at least 1.5 hour, or for at least 2 hours. Suchdelayed release oral dosage forms can release at least 40%, at least50%, at least 60%, at least 70%, at least 80% or at least 90% of thecrystalline form of the compound of Formula I thereof in the intestines(small intestines, large intestine/colon etc.).

In an aspect of the present disclosure, the enteric tablets, entericcaplets, and enteric capsules may be uncoated. Hard uncoated capsuleswith enteric capability using intrinsically enteric capsule technology(for example, EnTrinsic Drug Delivery available from Capsugel) aresuitable for the purpose of the present disclosure.

In various embodiments, the enteric tablet is a hard tablet made withfree-flowing powder of the crystalline form of the compound of Formula Ithereof. In various embodiments, the enteric capsule is a capsule madewith free-flowing powder of crystalline form of the the compound ofFormula I thereof. In various embodiments, the enteric tablet is a hardtablet made with free-flowing powder of the crystalline form of thecompound of Formula I. In various embodiments, the enteric capsule is acapsule made with free-flowing powder of the crystalline form of thecompound of Formula I.

In some embodiments, the enteric capsule is a non-animal-based capsule,such as a hypromellose capsule (for example, commercially availableself-gelling Vcaps, VCaps Plus, VCaps enteric, other enteric capsulesmade using Xcellodose, ENCODE colonic delivery technology, andEnTrinsic™ drug delivery technology from Capsugel). Other technologiesknown in the art and available commercially (for example, Qualicaps,USA, Nutrascience, USA, etc.) for the formulating enteric forms of oralsolid dosage forms can also be utilized. In at least one embodiment, thecapsule is an API-in-capsule, meaning that the crystalline form of thecompound of Formula I free base or salts thereof is filled neat into thecapsule. In such API-in-capsule oral dosage forms, the activeingredient, the crystalline form of the compound of Formula I can befree flowing powders or micronized powders. When the dosage Form I acapsule, in at least one embodiment, the capsule can be a seamlesscapsule or a banded capsule.

Dissolution of the oral dosage forms disclosed herein is tested by thedissolution tests according to the current methods of USP 711. In someembodiments, the oral dosage forms disclosed herein are protected fromthe acidic environment of the stomach and do not dissolve for at least 2hours, at least 3 hours, at least 4 hours, at least 5 hours, 6 hours, atleast 7 hours or at least 8 hours. In at least one embodiment, the oraldosage forms do not release PRX-3140 for at least 6 hours. In anotherembodiment, the oral dosage forms do not release PRX-3140 for at least 2hours.

VI. Methods of Making Pharmaceutical Compositions

In further embodiments, the present disclosure provides a method ofmaking a pharmaceutical composition wherein the method further comprisesformulating the particles.

In certain embodiments, the particles are formulated into unit dosessuch as tablets or capsules.

In some embodiments wherein the pharmaceutical compositions furthercomprises at least one excipient, the present disclosure also provides amethod of making a pharmaceutical composition wherein the method furthercomprises mixing the particles with at least one excipient to form asecond mixture; and formulating the second mixture.

In certain embodiments, the particles are formulated into unit dosessuch as tablets or capsules.

VII. Methods of Treatment

The pharmaceutical compositions described herein may be useful to treatany disease or condition for which administration of a correspondinginsoluble drug is desirable. For example, compositions comprisingcrystalline form of the compound of Formula I may be useful for thetreatment of Alzheimer's disease (AD) and other dementias affecting thecholinergic and/or serotonergic systems including post-traumatic stressdisorder (PTSD). The terms “treat,” “treatment,” and “treating” refer to(1) a reduction in severity or duration of a disease or condition, (2)the amelioration of one or more symptoms associated with a disease orcondition without necessarily curing the disease or condition. In someembodiments, the method of treatment further comprises the prevention ofa disease or condition. Suitable subjects include, e.g., humans andother mammals, such as, e.g., mice, rats, dogs, and non-human primates.

In yet another aspect, the disclosure provides a method of treatingAlzheimer's disease (AD) and other dementias affecting the cholinergicand/or serotonergic systems including post-traumatic stress disorder(PTSD), comprising administering an effective amount of a pharmaceuticalcomposition of the present disclosure to a patient in need thereof.

Other embodiments of the present disclosure will be apparent to thoseskilled in the art from consideration of the specification and practiceof the present disclosure disclosed herein. It is intended that thespecification and examples be considered as exemplary only, with thetrue scope and spirit of the present disclosure.

EXAMPLES

Example 1—Small-scale preparation of 50 grams of crystalline PRX-3140potassium salt. U.S. Pat. Nos. 7,488,736 and 7,982,040 describedPRX-3140 preparation in a six-step process. Supply of3-piperidin-1-yl-propylamine allows synthesis of crystalline fineparticle Form I of PRX-3140 potassium salt in four-step process at the50-gram scale as shown in FIG. 2 .

Step 1. Reductive amination—Methyl2-iso-propylaminothiophene-3-carboxylate (3). To a 3 L three-neckround-bottom flask equipped with a mechanical stirrer was added methyl2-aminothiophene-3-carboxylate (90.52 g, 0.5758 mol) and sodiumtriacetoxyborohydride (207.48 grams, 0.979 mole). Anhydrousdichloromethane (640 mL) was added and the mixture was stirred for 2minutes prior to the addition of a solution of formic acid (53.01 grams,1.1517 mole) and 2,2-dimeoxypropane (299.88 grams, 2.8793 mole) over 30minutes at 15-32.degree.C (internal temperature) under argon (cooledwith cold water if needed). The addition funnel was rinsed withanhydrous dichloromethane (92 mL) and charged to the reaction mixture.After the addition was completed, the resulting mixture was stirred at25-30.degree.C for 2 hours. The reaction mixture was added to an aqueoussolution of potassium hydroxide (304.1 gram, 4.607 mole) in water (905mL) at 5.degree.C and maintaining the temperature below 40.degree.C.Dichloromethane (100 mL) was used to rinse the reaction flask and addedto the mixture. The resulting mixture was stirred at room temperaturefor 0.5 hour, then filtered, and the residue was washed withdichloromethane (300 mL). The filtrate was diluted with water (0.5 L),and the phases were separated. The aqueous phase was extracted withdichloromethane (0.5 L). The combined organic phase was mixed with water(0.5 L) and stirred for 0.5 hour. The phases were separated again, andthe organic phase was dried over Na₂SO₄. Filtration and concentrationprovided 114.7 grams crude as red oil, which was dissolved in heptane(0.50 L) and stirred with neutral alumina (90 grams) for 0.5 hour, thenfiltered, and the filtrate was evaporated. The titled compound (105.8 g,92%) was obtained as yellowish oil. HPLC purity: 98.2%. 1H NMR (300 MHz,CDCl₃) δ 7.35 (br s, 1H), 7.00 (d, J=5.7 Hz, 1H), 6.14 (dd, J=5.7, 1.2Hz, 1H), 3.78 (s, 3H), 3.56-3.44 (m, 1H), 1.32 (s, 3H), 1.29 (s, 3H).

Step 2. Acylation and cyclization—Methyl4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylate(5). To a solution of starting amine 3 (89.7 grams, 0.450 mole) andpyridine (71.2 grams, 0.900 mole) in butyronitrile (0.9 L) was heated to70-75.degree.C with stirring under argon. A solution of methyl malonylchloride (116.7 grams, 0.855 mol) in butyronitrile (0.45 L) was addeddrop-wise to the reaction mixture to maintain the temperature at70-75.degree.C (internal temperature) with vigorous stirring (withoccasional turn off of the heating, especially in the beginning). At theend of addition, the temperature was held for 8 to 10 minutes beforesodium methoxide solution (25%, 390.0 grams, 415 mL, 1.80 mol) was addedover 10 minutes at the same temperature. The resulting mixture wasstirred at the same temperature for 10 minutes, then cooled to roomtemperature. Water (0.45 L) was added, and the mixture was stirred for20 minutes at room temperature. The phases were separated, and theorganic phase was extracted with water (0.45 L). The combined aqueousphase was washed with EtOAc (2×0.45 L). The aqueous phase was thenacidified to pH 4.0-4.5 with 1:5 v/v HCl/water at room temperature. Theresulting solid was filtered and washed with water (2×180 mL). Thefilter cake was dried on vacuum oven at 45-50.degree.C overnight. Titlecompound was obtained (68.48 g, 57%) as yellow solid. HPLC purity:98.1%. The filtrate was cloudy overnight and 2nd filtration provided 2ndcrop (9.68 g, 8%, HPLC purity: 87.4%), which was not used for next step.1H NMR (300 MHz, CDCl₃) δ 7.32 (d, J=5.7 Hz, 1H), 6.90 (d, J=6.0 Hz,1H), 4.00 (s, 3H), 1.70-1.60 (m, 1H), 1.64 (s, 3H), 1.61 (s, 3H).

Step 3. Amidation and salt formation4-Hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide hydrochloride (8). A mixture ofmethyl 4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridinecarboxylate (5, 2 grams, 7.48 mmol) and 3-piperidin-1-yl-propylamine (6,1.12 g, 7.85 mmol, 1.05 equiv.) was heated at 90-95.degree.C for 2hours. TLC analysis indicated that the reaction was complete. Thereaction mixture was cooled to room temperature, diluted with water (5mL), and charged with 1M HCl (7.4 mL). The organic layer was separatedand washed with water (4 mL). The organic layer was treated withconcentrated hydrochloric acid (1.4 grams). The organic phase wasconcentrated to ca. 11 mL (9.9 grams). The residue was charged withn-butanol (10 mL). The mixture was re-concentrated to a volume of ca. 11mL (9.9 grams). The residue was heated to 50.degree.C and diluted withMTBE (20 mL). The mixture was stirred at 50.degree.C for 40 minutes,cooled to room temperature, and then held at −10.degree.C overnight. Theslurry was filtered at 0-5.degree.C. The filter cake was washed withn-butanol/MTBE (1:3, 2×4 mL) and dried on rotavapor to give4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide hydrochloride (8, 2.35 grams,yield: 75%, HPLC: 99.65%) as a white solid. The batch started with 66.35g of ester 5 and 84.5 g of title compound 8 was obtained (yield: 82%).¹H NMR (300 MHz, DMSO-d₆) δ 10.24 (br t, J=5.4 Hz, 1H), 9.91 (br s, 1H),7.38 (d, J=5.7 Hz, 1H), 7.32 (d, J=5.7 Hz, 1H), 3.47-3.30 (m, 4H),3.08-2.98 (m, 2H), 2.90-2.76 (m, 2H), 2.05-1.93 (m, 2H), 1.82-1.62 (m,6H), 1.57 (s, 3H), 1.55 (s, 3H), 1.44-1.26 (m, 1H).

Step 4: Preparation of4-Hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide potassium salt (PRX-3140 potassiumsalt). A mixture of4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide hydrochloride (8, 2.35 g, 5.68mmol), MTBE (23.5 mL), water (11.75 mL) and 1M KOH solution (5.6 mL) wasstirred at room temperature for 20 minutes. The mixture still hadinsoluble hydrochloride salt. NaHCO₃ (0.49 gram) was added to abovemixture and continued to stir for 0.5 hour. The mixture became a clearsolution. The organic layer was separated. The aqueous layer wasextracted with additional MTBE (20 mL). The combined organic layers wereconcentrated to dryness to give4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide (2.17 grams) as free base.

The above free base (2.17 gram, 5.68 mmol) was dissolved in acetonitrile(23.5 mL) at 45-50.degree.C. To above solution was added a solution ofKOH (0.43 gram, 6.53 mmol) in water (1.8 mL). The resulting mixture wasstirred at 50.degree.C for 0.5 hours, cooled to room temperature, thencooled at 0-5.degree.C for 3 hours. The solid was filtered to give 3grams of wet product which was dissolved into a mixture of acetonitrile(42 mL) and water (3 mL) at 50.degree.C. The solution was filtered toremove insoluble solid. The filtrates were concentrated to a volume of21 mL. Acetonitrile (21 mL) was added and concentrated to a volume of 21mL. This process repeated twice. The residue was placed in ice-waterbath for 3 hours, filtered and the filter cake was washed withacetonitrile (at 0.degree.C, 2×6 mL), dried on rotavapor to givecrystalline4-hydroxy-7-isopropyl-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylicacid (3-piperidin-1-yl-propyl)-amide potassium salt (1.75 gram, yield:74.2%; HPLC: 99.9%, KF: 1.19%) as white solid. The batch started with84.5 grams of hydrochloride salt 8 converted to 76.3 grams ofcrystalline fine particle Form I of PRX-3140 potassium salt (yield: 90%;HPLC: 99.6%, KF: 0.66%). 1H NMR (300 MHz, DMSO-d₆) δ 10.79 (t, J=5.3 Hz,1H), 7.13 (d, J=5.4 Hz, 1H), 6.80 (d, J=5.4 Hz, 1H), 3.19-3.11 (m, 2H),2.70-2.40 (m, 6H), 1.62-1.30 (m, 15H).

Example 2—X-ray Diffraction of Crystalline PRX-3140 Potassium SaltPrepared at Two Scales. Crystalline fine particle Form I of PRX-3140potassium salt samples of Examples 1 and a scale-up batch were used toidentify differences in the crystalline structure of the two samplesthrough standard x-ray diffraction (XRD) measurement. In both examplesthe same peaks were obtained shown in FIGS. 3 and 4 as well as Tables 1and 2, respectively.

TABLE 1 XRD of Example 1 crystalline fine particle Form I of PRX-3140potassium salt Peak Value Peak (degree) Intensity 5.441 1087 11.875 45712.994 304 13.730 460 15.919 696 16.286 501 16.520 553 17.089 509 19.428254 19.879 172 20.331 536 20.648 160 21.266 524 21.601 566 22.303 193522.938 419 23.556 314 24.325 444 24.726 365 25.260 1325 25.829 93026.347 163 27.433 441 28.553 237 29.137 212 29.923 619 30.792 165 32.613306 33.081 481 34.435 382 34.853 223 35.789 246 36.440 274 36.891 17237.276 212 39.264 321 39.649 228 40.050 283 40.651 160 41.069 308 41.738204 42.456 314 43.225 209 43.793 280 44.746 327 44.930 339 45.297 39145.581 474 46.283 252 46.751 160 46.985 173 48.222 243 48.773 181 48.924164 49.308 176 49.676 165 50.578 228 52.617 190 53.937 172 54.355 17554.806 169 56.059 160 58.048 161

TABLE 2 XRD of Scale-up batch of crystalline fine particle Form I ofPRX-3140 potassium salt Peak Value Peak (degree) Intensity 5.444 23311.928 228 13.031 162 13.783 245 15.989 431 16.356 298 16.574 324 17.142294 19.498 203 20.400 321 21.336 371 21.654 374 22.389 1222 23.007 28023.609 247 24.378 342 24.812 295 25.330 810 25.898 637 26.734 161 27.486264 28.622 203 29.207 191 29.993 394 30.611 241 32.683 215 33.151 33834.438 269 35.507 160 35.842 189 36.159 160 36.527 206 37.312 200 38.432161 39.368 320 40.136 232 41.173 247 41.624 163 41.824 186 42.526 29443.144 171 43.295 197 43.796 213 43.947 220 44.849 298 45.668 369 46.303217 46.955 192 48.342 240 49.027 167 49.361 196 49.762 160 49.929 16050.648 205 50.965 160 51.818 161 52.737 165 53.957 160 54.241 160 54.408160 54.892 204 56.079 160 58.836 160

Example 3—PRX-3140 Potassium Salt Photostability Study. Two samples ofcrystalline fine particle Form I of PRX-3140 potassium salt wereprepared for photostability testing: (1) 1.5 grams spread evenly acrossa glass Petri dish and covered with a transparent quartz cover and (2)1.5 grams spread evenly across a glass Petri dish and covered withaluminum foil. Samples were exposed to ICH photostability guidelineQ1B=1.2 million lux hours of cool, white fluorescent light & 200 watthours/m2 of UVA light at 40.degree.C/75% RH. Samples were exposed for 2days and tested using HPLC.

The control photostability sample of PRX-3140 potassium salt met thespecification and showed HPLC results comparable to those obtained forthe t=0 sample although an increase in water content from 0.9% w/w to3.1% w/w was observed. The light exposure was performed in a cabinet setat 25.degree.C/60% RH. The sample was notably lumpy and requiredgrinding to obtain precise assay results.

TABLE 3 Photostability Study Exposed t = 0 Control Sample AppearanceLight Pinkish brown solid solid Orange Water Content-KF 0.9% w/w 3.1%w/w 4.3% w/w Total impurities 0.22% 0.20% 0.77% Unknown (RRT 0.55) 0.01%0.01% 0.01% Unknown (RRT 0.74) 0.01% 0.01% 0.02% Unknown (RRT 0.75)0.01% 0.01% 0.01% Unknown (RRT 0.86) nd nd 0.01% Unknown (RRT 0.87)0.09% 0.09% 0.10% Unknown (RRT 0.90) nd nd 0.01% Unknown (RRT 0.91) ndnd 0.01% Unknown (RRT 0.95) 0.05% 0.04% 0.05% Unknown (RRT 0.98) 0.01%0.01% 0.04% Unknown (RRT 1.07) nd 0.01% 0.06% Unknown (RRT 1.12) 0.01%0.01% 0.02% Unknown (RRT 1.22) 0.01% 0.01% 0.01% Unknown (RRT 1.50) ndnd 0.02% Unknown (RRT 1.54) nd nd 0.01% Unknown (RRT 1.57) nd nd 0.01%Unknown (RRT 1.63) nd nd 0.05% Unknown (RRT 1.72) nd nd 0.04% Unknown(RRT 1.72) nd nd 0.02% Unknown (RRT 1.75) nd nd 0.04% Unknown (RRT 1.76)nd nd 0.03% Unknown (RRT 1.79) nd nd 0.01% Unknown (RRT 1.83) nd nd0.16% Unknown (RRT 2.01) 0.01% nd nd Unknown (RRT 2.06) nd nd 0.01%Unknown (RRT 2.08) nd nd 0.01% Unknown (RRT 2.16) 0.01% nd 0.01% Unknown(RRT 2.38) 0.01% nd nd Key to table RRT = Relative Retention Time, nd =not detected

FIG. 4 shows the PRX-3140 potassium salt photostability study HPLCchromatograms (A) unexposed control sample and (B) PRX-3140 potassiumsalt photostability exposed sample. Changes were evident for crystallinefine particle Form I of PRX-3140 potassium salt after exposure to UVAand white light. The sample changed color particularly on the upperexposed surface of the material and there were changes apparent in theHPLC data. The illuminated photostability sample of PRX-3140 potassiumsalt met the USP stability specification of (1) total impurities notmore than 2.0% area and (2) no single impurity greater than 0.5% areawith a reported assay value of 94.2% w/w, which was below thespecification limit. The single impurity profile met the specification(<0.2%) but significant changes were observed. There was an increase inthe number of minor impurities, particularly in a region of thechromatogram between RRT 1.5 and 2.1. Total impurities increased from0.20% in the control sample to 0.77% in the exposed sample. An impurityat RRT 1.83 which was not present before exposure to light was formed at0.16% in the exposed sample. Other changes included a change inappearance of the material to a sticky solid and an increase in watercontent to 4.3% w/w.

Example 4—Crystalline PRX-3140 Potassium Salt Forced Degradation Study.Crystalline fine particle Form I of PRX-3140 potassium salt wassubjected to a forced degradation study using acid, base, or hydrogenperoxide exposure for 24 hours. Samples were neutralized and analyzedusing LC-UV-MS. Table 4 lists the LC-UV-MS conditions.

TABLE 4 LC-UV-MS conditions HPLC/MS Agilent LC/MSD 6120B SourceElectrospray (ESI) Method Gradient Diluent 20/80 Methanol/Water MobilePhase A Water with 0.1% Formic Acid Mobile Phase B Acetonitrile with0.1% Formic Acid Gradient 90/10 A/B -> 90/10 A/B (1 min) -> 40/60 A/B(20 min) -> 10/90 A/B (30 min) ->10/90 A/B (35 min) -> 90/10 A/B (35.5min) ->90/10 A/B (40 min) Column Waters Atlantis T3, 3 μm, 150 × 4.6 mmTemp 30.degree.C. Flow Rate 1 mL/min Injection Volume 10 uL UV Detection250, 220, and 320 nm Scan 125 to 1000 m/z Step Size 0.1 m/z Fragmentor150 V Gain  5 Threshold 100 Drying Gas 325.degree.C. Capillary 3000 VNebulizer Gas 7 LPM

Control Sample: FIG. 6A is HPLC UV chromatogram of the crystalline fineparticle Form I of PRX-3140 potassium salt Standard (Control) at 250 nm.The UV spectra for the parent molecule is shown in FIG. 6B. Maximums arenoted at 220, 250, and 320 nm. Chromatograms for all samples werecollected at all three wavelengths with 250 nm being the primarywavelength based on lambda max. The starting material was 98.6% purebased on peak area at 250 nm. The mass spectra at 12.2 minutes for theparent molecule, PRX-3140, is shown in FIG. 6C. The protonated PRX-3140molecular ion, [M+H]+, is noted at 378.2 m/z.

Sample Preparation: Crystalline fine particle Form I of PRX-3140potassium salt, 50 mg, was weighed out into a 25 mL volumetric flask andtaken to volume with water (2 mg/mL stock). One mL of stock was added tofour, 4 mL vials. One mL of either 1N HCl, 1N NaOH, 3% H2O2, or DI Water(control) was added to the appropriate vial, mixed, and stored at roomtemperature for 24 hours. After storage, the samples of acid and basewere neutralized by addition of 1 mL their counter solution. One mL ofwater was added to the peroxide sample and the control so that allsamples had a final concentration of 0.67 mg/mL. Samples were analyzedusing LC-UV-MS.

Table 5 lists a comparison for the control, acid, base, and peroxidesamples showing percent peak area versus relative retention time (RRT)at 250 nm. While some minor changes can be noted between the controlwith the acid and base samples, the overall purity (peak area) of theparent molecule is just slightly higher for the acid and base sample.Some of the minor impurities appear to be reacting with the acid orbase, potentially reforming to the parent. The greatest change in puritywas noted in the peroxide sample where 2 major impurities were formedand the purity at 250 nm went from 98.6 to 80.6%.

TABLE 5 PRX-3140 Potassium Salt Forced Degradation Study RRT ControlAcid Base H2O2 0.78 8.49 0.82 0.10 0.94 0.28 0.99 0.07 1.00 98.60 98.9498.71 80.57 1.05 <0.03 <0.03 <0.03 9.06 1.08 0.12 0.11 0.12 0.19 1.110.04 0.04 1.27 0.04 0.21 1.34 0.17 0.15 0.16 0.09 1.42 0.32 1.53 0.420.43 0.42 0.42 1.71 0.23 1.79 0.11 0.04 0.05 0.19 1.93 0.06 2.51 0.060.06 0.05 2.70 0.18 0.13 0.12 0.11

Acid Degradation Sample: Based on the purity peak area at 250 nm, thecontrol was 98.6% and the acid sample was 98.9%. 1 N HCl for 24 hourshad very little effect on PRX-3140 potassium salt.

Base Degradation Sample: Based on the purity peak area at 250 nm, thecontrol was 98.6% and the base sample was 98.7%. 1 N NaOH for 24 hourshad very little effect on PRX-3140 potassium salt.

Peroxide Degradation Sample: The UV chromatogram for the peroxidedegradation sample at 250 nm is shown in FIG. 7A full scale. Two majorimpurity peaks are noted at 9.6 and 13.3 minutes (RRT 0.78 and 1.05respectively). Based on the purity peak area at 250 nm, the control was98.6% and the peroxide sample was 80.6%. Hydrogen peroxide, 3%, for 24hours reacted with PRX-3140 and formed 2 major degradants.

FIG. 7B is the mass spectra of PRX-3140a at 9.6 minutes (RRT 0.78). An[M+H]+ is noted at 258.0 m/z with an ammonium adduct [M+H+NH3]+ at275.1, a sodium adduct [M+Na]+ at 280.1, and sodium dimer [2M+Na]+ at537.1 m/z. It is noted that this is a fragile molecule and required thereduction of the Fragmentor Voltage from 150 down to 70V to see theprotonated molecular ion. At the higher voltage, molecule fragments werenoted at 216.0, 198.0, and 152.0. The proposed structure of PRX-3140a isFormula II: ##STR00002 ##:5-hydroxy-8-(methylethyl)-8-hydro-1,2-oxathiino[6.5-b]pyridine-2,2,7-trione,or5-hydroxy-8-(propan-2-yl)-2H-2λ6-[1,2]oxathiino[6,5-b]pyridine-2,2,7(8H)-trionewith the chemical formula of C10H11NO5S and is shown in FIG. 5 .

FIG. 7C is the mass spectra of PRX-3140b at 13.3 minutes (RRT 1.05). An[M+H]+ is noted at 394.2 m/z with [2M+H]+ at 787.4 m/z. This compound isnoted in the control, acid, and base samples but at a very low level(<0.03%). In the peroxide sample, this peak is 9.1%. The proposedstructure of PRX-3140b is Formula III: ##STR00003 ##:[7-(methylethyl)1,4,6-trioxo(5,7-dihydrothiopheno[2,3-b]pyridine-5-yl)]-N-(3-piperidylpropyl)carboxamide,or1,4,6-trioxo-N-[3-(piperidin-1-yl)propyl]-7-(propan-2-yl)-4,5,6,7-tetrahydro-1H-1λ4-thieno[2,3-b]pyridine-5-carboxamidewith the chemical formula of C19H27N3O4S and is shown in FIG. 5 .

Example 5—PRX-3140 30% Peroxide Degradation Study. Crystalline fineparticle Form I of PRX-3140 potassium salt was subjected to a secondforced degradation experiment using 30% hydrogen peroxide exposure for24 hours. Sample was evaporated to dryness and analyzed using LC/UV/MSand NMR analysis. Two major degradants are noted in the LC/UV/MS.

Sample Preparation: 60 mg (55 μL) of 30% hydrogen peroxide (0.5 mmol)was added dropwise to a suspension of starting PRX-3140 potassium salt(208 mg, 0.5 mmol) in 5 mL of dry acetone at 0.degree.C. The resultingsuspension was stirred under argon and warmed to RT spontaneouslyovernight (18 hours). The solvent is removed under vacuum at RT, thenacetonitrile (5 mL) was added to the residue and evaporated to drynessat 40.degree.C. The PRX-3140 30% peroxide sample residue weighed 300 mg.

1H NMR of the crude 30% peroxide sample is shown in FIG. 8A. Forcomparison, 1H NMR of PRX-3140 potassium salt is shown in FIG. 8B.

A solid portion of the PRX-3140 30% peroxide sample was submitted forLC/UV/MS analysis. Two milligrams of the sample was weighed into a 4 mLvial. Two mL of 20/80 methanol/water was added to the vial and vortexedvigorously. FIG. 9A is a HPLC chromatogram of the H₂O₂ sample at 250 nm.Three major peaks are noted, including the parent molecule at 12.5minutes. A purity of 29.6% is noted for the parent molecule PRX-3140following 18-hour exposure to 30% hydrogen peroxide. The UV spectra forthe parent molecule at 12.5 min is shown in FIG. 9B. Maximums are notedat 220, 250, and 320 nm. Chromatograms for all samples were collected atall three wavelengths with 250 nm as the primary wavelength based onlambda max (λmax). FIG. 10A is the UV spectra for the peak at 8.9minutes. In comparison with the parent molecule, the high-end absorptionis absent (320 nm). FIG. 10B is the UV spectra for the peak at 12.9minutes. The spectra are identical to the parent molecule noted in FIG.9B. The mass spectra at 12.5 minutes for the parent molecule, PRX-3140,is shown in FIG. 11A. The protonated molecular ion, [M+H]+, is noted at378.2 m/z. FIG. 11B is the mass spectra of PRX-3140a at 8.9 minutes (RRT0.73 compared to 0.78 in Example 4). An [M+H]+ is noted at 258.0 m/zwith [M+H+NH3]+ at 275.1, [M+Na]+ at 280.1, and [2M+Na]+ at 537.1 m/z.It is noted that this is a fragile molecule and required the reductionof the Fragmentor Voltage from 150V down to 70V to see the protonatedmolecular ion. At the higher voltage, molecule fragments were noted at216.0, 198.0, and 152.0. A proposed structure of PRX-3140a is shown inFIG. 5 . FIG. 11C is the mass spectra of the largest degradation productof PRX-3140b at 12.9 minutes, relative retention time (RRT) of 1.04(compared to 1.05 in Example 4). The [M+H]+ of 394.2 m/z is potentiallythe parent molecule plus oxygen (+0). The proposed structure ofPRX-3140B is shown in FIG. 5 .

Example 6—PRX-3140 Excipient Compatibility Study. Excipient testing andcompatibility studies were performed on the crystalline fine particleForm I of PRX-3140 potassium salt. We conducted excipient compatibilitystudies for binary blends (50:50 w/w) with the crystalline fine particleForm I of PRX-3140 potassium salt sample mixed with (1) Starch,pregelatinized, NF (Colorcon), (2) Microcrystalline Cellulose (AvicelPH-105, DuPont), (3) Magnesium Stearate NF (Avantor), (4) Stearic Acid,NF (Letco), (5) Lecithin, Granular Food Grade (Spectrum), (6)Polyethylene Glycol 3,350, USP (Dow), (7) HPB-Cyclodextrin (CTD), (8)Silicon Dioxide, FCC (Spectrum), and (9) Mannitol USP (Spectrum).Samples were analyzed by HPLC assay described in Example 2. Samplesstored at 40.degree.C/75% RH and assay and purity tested by LC-UV-MS at0, 30, 60, and 90 days. At each timepoint powder samples were weighedand diluted at 50:50 methanol:DI water. Samples for HPLC analysis werefiltered through a 0.45 micron PTFE filter for injection.

TABLE xx PRX- Assay % Purity 3140b % Sample Timepoint Color PRX-3140PRX-3140 RRT 1.06 Impurities Control  0 White 98.8 98.69 0.03 1.31 30days White 100.9 98.74 0.03 1.26 60 days White 99.5 98.74 0.03 1.26 90days White 100.3 98.63 0.04 1.27 Starch  0 White 100.0 98.79 0.02 1.2130 days White- 96.1 98.59 0.04 1.36 Yellow 60 days White- 96.2 98.780.05 1.17 Yellow 90 days White- 96.2 98.71 0.05 1.20 Yellow MCC  0 White100.0 98.73 0.03 1.27 30 days White- 99.3 98.72 0.04 1.28 Yellow 60 daysWhite- 97.4 98.81 0.04 1.19 Yellow 90 days White- 98.9 98.81 0.05 1.20Yellow Magnesium  0 White 100.0 98.76 0.03 1.24 Stearate 30 days White82.2 98.85 0.05 1.15 60 days White 83.5 98.93 0.05 1.17 90 days White89.4 98.91 0.05 1.09 Stearic  0 White 100.0 98.77 0.03 1.23 Acid 30 daysWhite- 100.1 98.86 0.06 1.14 Yellow 60 days White- 94.2 98.90 0.06 1.02Yellow 90 days White- 89.4 99.00 0.07 1.00 Yellow Lecithin  0 Tan 100.098.76 0.03 1.24 30 days Tan 99.1 98.37 0.49 1.59 60 days Tan-Brown 92.998.08 0.67 1.85 90 days Tan-Brown 94.9 97.84 1.09 2.12 PEG 3350  0 White100.0 98.78 0.02 1.22 30 days White- 97.1 98.70 0.05 1.30 Yellow 60 daysWhite- 96.5 98.73 0.06 1.27 Yellow 90 days White- 94.4 98.57 0.08 1.30Yellow HPBCD  0 White 100.0 98.76 0.02 1.24 30 days White 96.4 98.760.03 1.24 60 days White 94.1 98.69 0.03 1.29 90 days White 94.7 98.750.03 1.15 Silicon  0 White 100.0 98.77 0.03 1.23 Dioxide 30 days White93.2 98.74 0.03 1.26 60 days White 84.6 98.84 0.03 1.16 90 days White85.2 98.89 0.04 1.10 Mannitol  0 White 100.0 98.77 0.02 1.23 30 daysWhite 96.1 98.77 0.03 1.23 60 days White 96.2 98.81 0.03 1.17 90 daysWhite 96.2 98.57 0.03 1.20

The PRX-3140: lecithin (50:50) sample degraded over the 90 day study andthe PRX-3140a degradation product (RRT 1.06) increased to over 1%. FIG.12A shows the PRX-3140: lecithin (50:50) Time 0 sample and FIG. 12Bshows the 90 day sample demonstrating an increase of PRX-3140B (RRT1.05) at 90 days at 40.degree.C.

Example 7—Preparation of PRX-3140 Potassium Salt PDS. A mass of 10 g ofcrystalline fine particle Form I of PRX-3140 potassium salt (AlchemLaboratories Corp.) and 10 g of Microcrystalline Cellulose (AvicelPH-105, DuPont) was mixed in 50 mL tube. The powder was then ground intoa fine powder using a Retsch mill. Particles smaller than 600 micronswere separated by sieving (30 mesh). The resulting white powder wasobtained with a yield of >90% crystalline PRX-3140 potassium salt PDSpowder, containing particles with a diameter less than 500 microns.

Example 8—Preparation of Immediate-Release Oral PRX-3140 Potassium SaltCapsules. An immediate-release oral dosage form (gelatin capsules)containing the crystalline fine particle Form I of PRX-3140 potassiumsalt particles prepared in Example 7 was dry mixed with additionalMicrocrystalline Cellulose (Avicel PH-105, DuPont) to achieve thecorrect capsule fill weight (400-500 mg) to achieve the desired dose.Clear gelatin #1 capsules were then filled with the mixture in a TorpacProfill 3700 machine to yield capsules containing 320 mg of PRX-3140potassium salt PDS with 50 mg PRX-3140. Samples were taken to verifyloading uniformity, content uniformity, and dissolution time.

Example 9—Dissolution of Immediate-Release Oral PRX-3140 Potassium Salt.Capsules from Example 8 were exposed to acidic buffer for 60 minutes tomimic the stomach environment. To demonstrate dissolution, more than 75%release of PRX-3140 in solution at 15 to 30 minutes in acidic buffer wastested using a USP dissolution apparatus and HPLC.

What is claimed is:
 1. A composition comprising a crystalline form of acompound of Formula I ##STR00001##

wherein the crystalline form is Form I characterized by an x-ray powderdiffraction pattern comprising at least one peak selected from22.3+/−0.3 degrees, 25.3+/−0.3 degrees, 5.4+/−0.3 degrees, 25.8+/−0.3degrees, 15.9+/−0.3 degrees, 29.9+/−0.3 degrees, 21.6+/−0.3 degrees,16.5+/−0.3 degrees and 20.3 degrees two theta; wherein the crystallineform is Form I characterized by an x-ray powder diffraction patternsubstantially as set forth in FIG. 3A or FIG. 3B.
 2. The composition ofclaim 1, wherein greater than 90% by weight of the compound of FormulaI: ##STR00001## is the crystalline form of Form I characterized by anx-ray powder diffraction pattern comprising major peaks at 22.3+/−0.3degrees, 25.3+/−0.3 degrees and 5.4+/−0.3 degrees two theta.
 3. Thecomposition of claim 1, wherein the compound of Formula I: ##STR00001##is the crystalline form of Form I characterized by an x-ray powderdiffraction pattern comprising major peaks at 22.3+/−0.3 degrees,25.3+/−0.3 degrees and 5.4+/−0.3 degrees two theta and is present in anamount ranging from about 0.01% to about 99.99% by mass of thecomposition.
 4. The composition of claim 1, wherein the composition hascrystalline particles of a compound of Formula I: ##STR00001## with anaverage diameter of less than about 1 mm.
 5. The composition of claim 1,wherein the composition has crystalline particles of a compound ofFormula I: ##STR00001## with an average diameter of less than about 500μm.
 6. The composition of claim 1, wherein the compound is stable for atleast 12 months at 5 degrees Celsius and 60% relative humidity or at 25degrees Celsius and 60% relative humidity.
 7. A method of treatingAlzheimer's disease (AD) and other dementias affecting the cholinergicand/or serotonergic systems, comprising administering an effectiveamount of the composition of claim 1 to a patient in need thereof.